update windows build to Python 3.7

Lib/lib2to3/Grammar.txt

@@ -0,0 +1,154 @@
+# Grammar for 2to3. This grammar supports Python 2.x and 3.x.
+
+# NOTE WELL: You should also follow all the steps listed at
+# https://devguide.python.org/grammar/
+
+# Start symbols for the grammar:
+#	file_input is a module or sequence of commands read from an input file;
+#	single_input is a single interactive statement;
+#	eval_input is the input for the eval() and input() functions.
+# NB: compound_stmt in single_input is followed by extra NEWLINE!
+file_input: (NEWLINE | stmt)* ENDMARKER
+single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
+eval_input: testlist NEWLINE* ENDMARKER
+
+decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
+decorators: decorator+
+decorated: decorators (classdef | funcdef | async_funcdef)
+async_funcdef: ASYNC funcdef
+funcdef: 'def' NAME parameters ['->' test] ':' suite
+parameters: '(' [typedargslist] ')'
+typedargslist: ((tfpdef ['=' test] ',')*
+                ('*' [tname] (',' tname ['=' test])* [',' ['**' tname [',']]] | '**' tname [','])
+                | tfpdef ['=' test] (',' tfpdef ['=' test])* [','])
+tname: NAME [':' test]
+tfpdef: tname | '(' tfplist ')'
+tfplist: tfpdef (',' tfpdef)* [',']
+varargslist: ((vfpdef ['=' test] ',')*
+              ('*' [vname] (',' vname ['=' test])*  [',' ['**' vname [',']]] | '**' vname [','])
+              | vfpdef ['=' test] (',' vfpdef ['=' test])* [','])
+vname: NAME
+vfpdef: vname | '(' vfplist ')'
+vfplist: vfpdef (',' vfpdef)* [',']
+
+stmt: simple_stmt | compound_stmt
+simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
+small_stmt: (expr_stmt | print_stmt  | del_stmt | pass_stmt | flow_stmt |
+             import_stmt | global_stmt | exec_stmt | assert_stmt)
+expr_stmt: testlist_star_expr (annassign | augassign (yield_expr|testlist) |
+                     ('=' (yield_expr|testlist_star_expr))*)
+annassign: ':' test ['=' test]
+testlist_star_expr: (test|star_expr) (',' (test|star_expr))* [',']
+augassign: ('+=' | '-=' | '*=' | '@=' | '/=' | '%=' | '&=' | '|=' | '^=' |
+            '<<=' | '>>=' | '**=' | '//=')
+# For normal and annotated assignments, additional restrictions enforced by the interpreter
+print_stmt: 'print' ( [ test (',' test)* [','] ] |
+                      '>>' test [ (',' test)+ [','] ] )
+del_stmt: 'del' exprlist
+pass_stmt: 'pass'
+flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt | yield_stmt
+break_stmt: 'break'
+continue_stmt: 'continue'
+return_stmt: 'return' [testlist]
+yield_stmt: yield_expr
+raise_stmt: 'raise' [test ['from' test | ',' test [',' test]]]
+import_stmt: import_name | import_from
+import_name: 'import' dotted_as_names
+import_from: ('from' ('.'* dotted_name | '.'+)
+              'import' ('*' | '(' import_as_names ')' | import_as_names))
+import_as_name: NAME ['as' NAME]
+dotted_as_name: dotted_name ['as' NAME]
+import_as_names: import_as_name (',' import_as_name)* [',']
+dotted_as_names: dotted_as_name (',' dotted_as_name)*
+dotted_name: NAME ('.' NAME)*
+global_stmt: ('global' | 'nonlocal') NAME (',' NAME)*
+exec_stmt: 'exec' expr ['in' test [',' test]]
+assert_stmt: 'assert' test [',' test]
+
+compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated | async_stmt
+async_stmt: ASYNC (funcdef | with_stmt | for_stmt)
+if_stmt: 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite]
+while_stmt: 'while' test ':' suite ['else' ':' suite]
+for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite]
+try_stmt: ('try' ':' suite
+           ((except_clause ':' suite)+
+	    ['else' ':' suite]
+	    ['finally' ':' suite] |
+	   'finally' ':' suite))
+with_stmt: 'with' with_item (',' with_item)*  ':' suite
+with_item: test ['as' expr]
+with_var: 'as' expr
+# NB compile.c makes sure that the default except clause is last
+except_clause: 'except' [test [(',' | 'as') test]]
+suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT
+
+# Backward compatibility cruft to support:
+# [ x for x in lambda: True, lambda: False if x() ]
+# even while also allowing:
+# lambda x: 5 if x else 2
+# (But not a mix of the two)
+testlist_safe: old_test [(',' old_test)+ [',']]
+old_test: or_test | old_lambdef
+old_lambdef: 'lambda' [varargslist] ':' old_test
+
+test: or_test ['if' or_test 'else' test] | lambdef
+or_test: and_test ('or' and_test)*
+and_test: not_test ('and' not_test)*
+not_test: 'not' not_test | comparison
+comparison: expr (comp_op expr)*
+comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
+star_expr: '*' expr
+expr: xor_expr ('|' xor_expr)*
+xor_expr: and_expr ('^' and_expr)*
+and_expr: shift_expr ('&' shift_expr)*
+shift_expr: arith_expr (('<<'|'>>') arith_expr)*
+arith_expr: term (('+'|'-') term)*
+term: factor (('*'|'@'|'/'|'%'|'//') factor)*
+factor: ('+'|'-'|'~') factor | power
+power: [AWAIT] atom trailer* ['**' factor]
+atom: ('(' [yield_expr|testlist_gexp] ')' |
+       '[' [listmaker] ']' |
+       '{' [dictsetmaker] '}' |
+       '`' testlist1 '`' |
+       NAME | NUMBER | STRING+ | '.' '.' '.')
+listmaker: (test|star_expr) ( comp_for | (',' (test|star_expr))* [','] )
+testlist_gexp: (test|star_expr) ( comp_for | (',' (test|star_expr))* [','] )
+lambdef: 'lambda' [varargslist] ':' test
+trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
+subscriptlist: subscript (',' subscript)* [',']
+subscript: test | [test] ':' [test] [sliceop]
+sliceop: ':' [test]
+exprlist: (expr|star_expr) (',' (expr|star_expr))* [',']
+testlist: test (',' test)* [',']
+dictsetmaker: ( ((test ':' test | '**' expr)
+                 (comp_for | (',' (test ':' test | '**' expr))* [','])) |
+                ((test | star_expr)
+		 (comp_for | (',' (test | star_expr))* [','])) )
+
+classdef: 'class' NAME ['(' [arglist] ')'] ':' suite
+
+arglist: argument (',' argument)* [',']
+
+# "test '=' test" is really "keyword '=' test", but we have no such token.
+# These need to be in a single rule to avoid grammar that is ambiguous
+# to our LL(1) parser. Even though 'test' includes '*expr' in star_expr,
+# we explicitly match '*' here, too, to give it proper precedence.
+# Illegal combinations and orderings are blocked in ast.c:
+# multiple (test comp_for) arguments are blocked; keyword unpackings
+# that precede iterable unpackings are blocked; etc.
+argument: ( test [comp_for] |
+            test '=' test |
+	    '**' expr |
+	    star_expr )
+
+comp_iter: comp_for | comp_if
+comp_for: [ASYNC] 'for' exprlist 'in' testlist_safe [comp_iter]
+comp_if: 'if' old_test [comp_iter]
+
+testlist1: test (',' test)*
+
+# not used in grammar, but may appear in "node" passed from Parser to Compiler
+encoding_decl: NAME
+
+yield_expr: 'yield' [yield_arg]
+yield_arg: 'from' test | testlist

Lib/lib2to3/PatternGrammar.txt

@@ -0,0 +1,28 @@
+# Copyright 2006 Google, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+# A grammar to describe tree matching patterns.
+# Not shown here:
+# - 'TOKEN' stands for any token (leaf node)
+# - 'any' stands for any node (leaf or interior)
+# With 'any' we can still specify the sub-structure.
+
+# The start symbol is 'Matcher'.
+
+Matcher: Alternatives ENDMARKER
+
+Alternatives: Alternative ('|' Alternative)*
+
+Alternative: (Unit | NegatedUnit)+
+
+Unit: [NAME '='] ( STRING [Repeater]
+                 | NAME [Details] [Repeater]
+                 | '(' Alternatives ')' [Repeater]
+                 | '[' Alternatives ']'
+		 )
+
+NegatedUnit: 'not' (STRING | NAME [Details] | '(' Alternatives ')')
+
+Repeater: '*' | '+' | '{' NUMBER [',' NUMBER] '}'
+
+Details: '<' Alternatives '>'

Lib/lib2to3/__init__.py

@@ -0,0 +1 @@
+#empty

Lib/lib2to3/__main__.py

@@ -0,0 +1,4 @@
+import sys
+from .main import main
+
+sys.exit(main("lib2to3.fixes"))

Lib/lib2to3/btm_matcher.py

@@ -0,0 +1,163 @@
+"""A bottom-up tree matching algorithm implementation meant to speed
+up 2to3's matching process. After the tree patterns are reduced to
+their rarest linear path, a linear Aho-Corasick automaton is
+created. The linear automaton traverses the linear paths from the
+leaves to the root of the AST and returns a set of nodes for further
+matching. This reduces significantly the number of candidate nodes."""
+
+__author__ = "George Boutsioukis <gboutsioukis@gmail.com>"
+
+import logging
+import itertools
+from collections import defaultdict
+
+from . import pytree
+from .btm_utils import reduce_tree
+
+class BMNode(object):
+    """Class for a node of the Aho-Corasick automaton used in matching"""
+    count = itertools.count()
+    def __init__(self):
+        self.transition_table = {}
+        self.fixers = []
+        self.id = next(BMNode.count)
+        self.content = ''
+
+class BottomMatcher(object):
+    """The main matcher class. After instantiating the patterns should
+    be added using the add_fixer method"""
+
+    def __init__(self):
+        self.match = set()
+        self.root = BMNode()
+        self.nodes = [self.root]
+        self.fixers = []
+        self.logger = logging.getLogger("RefactoringTool")
+
+    def add_fixer(self, fixer):
+        """Reduces a fixer's pattern tree to a linear path and adds it
+        to the matcher(a common Aho-Corasick automaton). The fixer is
+        appended on the matching states and called when they are
+        reached"""
+        self.fixers.append(fixer)
+        tree = reduce_tree(fixer.pattern_tree)
+        linear = tree.get_linear_subpattern()
+        match_nodes = self.add(linear, start=self.root)
+        for match_node in match_nodes:
+            match_node.fixers.append(fixer)
+
+    def add(self, pattern, start):
+        "Recursively adds a linear pattern to the AC automaton"
+        #print("adding pattern", pattern, "to", start)
+        if not pattern:
+            #print("empty pattern")
+            return [start]
+        if isinstance(pattern[0], tuple):
+            #alternatives
+            #print("alternatives")
+            match_nodes = []
+            for alternative in pattern[0]:
+                #add all alternatives, and add the rest of the pattern
+                #to each end node
+                end_nodes = self.add(alternative, start=start)
+                for end in end_nodes:
+                    match_nodes.extend(self.add(pattern[1:], end))
+            return match_nodes
+        else:
+            #single token
+            #not last
+            if pattern[0] not in start.transition_table:
+                #transition did not exist, create new
+                next_node = BMNode()
+                start.transition_table[pattern[0]] = next_node
+            else:
+                #transition exists already, follow
+                next_node = start.transition_table[pattern[0]]
+
+            if pattern[1:]:
+                end_nodes = self.add(pattern[1:], start=next_node)
+            else:
+                end_nodes = [next_node]
+            return end_nodes
+
+    def run(self, leaves):
+        """The main interface with the bottom matcher. The tree is
+        traversed from the bottom using the constructed
+        automaton. Nodes are only checked once as the tree is
+        retraversed. When the automaton fails, we give it one more
+        shot(in case the above tree matches as a whole with the
+        rejected leaf), then we break for the next leaf. There is the
+        special case of multiple arguments(see code comments) where we
+        recheck the nodes
+
+        Args:
+           The leaves of the AST tree to be matched
+
+        Returns:
+           A dictionary of node matches with fixers as the keys
+        """
+        current_ac_node = self.root
+        results = defaultdict(list)
+        for leaf in leaves:
+            current_ast_node = leaf
+            while current_ast_node:
+                current_ast_node.was_checked = True
+                for child in current_ast_node.children:
+                    # multiple statements, recheck
+                    if isinstance(child, pytree.Leaf) and child.value == ";":
+                        current_ast_node.was_checked = False
+                        break
+                if current_ast_node.type == 1:
+                    #name
+                    node_token = current_ast_node.value
+                else:
+                    node_token = current_ast_node.type
+
+                if node_token in current_ac_node.transition_table:
+                    #token matches
+                    current_ac_node = current_ac_node.transition_table[node_token]
+                    for fixer in current_ac_node.fixers:
+                        results[fixer].append(current_ast_node)
+                else:
+                    #matching failed, reset automaton
+                    current_ac_node = self.root
+                    if (current_ast_node.parent is not None
+                        and current_ast_node.parent.was_checked):
+                        #the rest of the tree upwards has been checked, next leaf
+                        break
+
+                    #recheck the rejected node once from the root
+                    if node_token in current_ac_node.transition_table:
+                        #token matches
+                        current_ac_node = current_ac_node.transition_table[node_token]
+                        for fixer in current_ac_node.fixers:
+                            results[fixer].append(current_ast_node)
+
+                current_ast_node = current_ast_node.parent
+        return results
+
+    def print_ac(self):
+        "Prints a graphviz diagram of the BM automaton(for debugging)"
+        print("digraph g{")
+        def print_node(node):
+            for subnode_key in node.transition_table.keys():
+                subnode = node.transition_table[subnode_key]
+                print("%d -> %d [label=%s] //%s" %
+                      (node.id, subnode.id, type_repr(subnode_key), str(subnode.fixers)))
+                if subnode_key == 1:
+                    print(subnode.content)
+                print_node(subnode)
+        print_node(self.root)
+        print("}")
+
+# taken from pytree.py for debugging; only used by print_ac
+_type_reprs = {}
+def type_repr(type_num):
+    global _type_reprs
+    if not _type_reprs:
+        from .pygram import python_symbols
+        # printing tokens is possible but not as useful
+        # from .pgen2 import token // token.__dict__.items():
+        for name, val in python_symbols.__dict__.items():
+            if type(val) == int: _type_reprs[val] = name
+    return _type_reprs.setdefault(type_num, type_num)

Lib/lib2to3/btm_utils.py

@@ -0,0 +1,281 @@
+"Utility functions used by the btm_matcher module"
+
+from . import pytree
+from .pgen2 import grammar, token
+from .pygram import pattern_symbols, python_symbols
+
+syms = pattern_symbols
+pysyms = python_symbols
+tokens = grammar.opmap
+token_labels = token
+
+TYPE_ANY = -1
+TYPE_ALTERNATIVES = -2
+TYPE_GROUP = -3
+
+class MinNode(object):
+    """This class serves as an intermediate representation of the
+    pattern tree during the conversion to sets of leaf-to-root
+    subpatterns"""
+
+    def __init__(self, type=None, name=None):
+        self.type = type
+        self.name = name
+        self.children = []
+        self.leaf = False
+        self.parent = None
+        self.alternatives = []
+        self.group = []
+
+    def __repr__(self):
+        return str(self.type) + ' ' + str(self.name)
+
+    def leaf_to_root(self):
+        """Internal method. Returns a characteristic path of the
+        pattern tree. This method must be run for all leaves until the
+        linear subpatterns are merged into a single"""
+        node = self
+        subp = []
+        while node:
+            if node.type == TYPE_ALTERNATIVES:
+                node.alternatives.append(subp)
+                if len(node.alternatives) == len(node.children):
+                    #last alternative
+                    subp = [tuple(node.alternatives)]
+                    node.alternatives = []
+                    node = node.parent
+                    continue
+                else:
+                    node = node.parent
+                    subp = None
+                    break
+
+            if node.type == TYPE_GROUP:
+                node.group.append(subp)
+                #probably should check the number of leaves
+                if len(node.group) == len(node.children):
+                    subp = get_characteristic_subpattern(node.group)
+                    node.group = []
+                    node = node.parent
+                    continue
+                else:
+                    node = node.parent
+                    subp = None
+                    break
+
+            if node.type == token_labels.NAME and node.name:
+                #in case of type=name, use the name instead
+                subp.append(node.name)
+            else:
+                subp.append(node.type)
+
+            node = node.parent
+        return subp
+
+    def get_linear_subpattern(self):
+        """Drives the leaf_to_root method. The reason that
+        leaf_to_root must be run multiple times is because we need to
+        reject 'group' matches; for example the alternative form
+        (a | b c) creates a group [b c] that needs to be matched. Since
+        matching multiple linear patterns overcomes the automaton's
+        capabilities, leaf_to_root merges each group into a single
+        choice based on 'characteristic'ity,
+
+        i.e. (a|b c) -> (a|b) if b more characteristic than c
+
+        Returns: The most 'characteristic'(as defined by
+          get_characteristic_subpattern) path for the compiled pattern
+          tree.
+        """
+
+        for l in self.leaves():
+            subp = l.leaf_to_root()
+            if subp:
+                return subp
+
+    def leaves(self):
+        "Generator that returns the leaves of the tree"
+        for child in self.children:
+            yield from child.leaves()
+        if not self.children:
+            yield self
+
+def reduce_tree(node, parent=None):
+    """
+    Internal function. Reduces a compiled pattern tree to an
+    intermediate representation suitable for feeding the
+    automaton. This also trims off any optional pattern elements(like
+    [a], a*).
+    """
+
+    new_node = None
+    #switch on the node type
+    if node.type == syms.Matcher:
+        #skip
+        node = node.children[0]
+
+    if node.type == syms.Alternatives  :
+        #2 cases
+        if len(node.children) <= 2:
+            #just a single 'Alternative', skip this node
+            new_node = reduce_tree(node.children[0], parent)
+        else:
+            #real alternatives
+            new_node = MinNode(type=TYPE_ALTERNATIVES)
+            #skip odd children('|' tokens)
+            for child in node.children:
+                if node.children.index(child)%2:
+                    continue
+                reduced = reduce_tree(child, new_node)
+                if reduced is not None:
+                    new_node.children.append(reduced)
+    elif node.type == syms.Alternative:
+        if len(node.children) > 1:
+
+            new_node = MinNode(type=TYPE_GROUP)
+            for child in node.children:
+                reduced = reduce_tree(child, new_node)
+                if reduced:
+                    new_node.children.append(reduced)
+            if not new_node.children:
+                # delete the group if all of the children were reduced to None
+                new_node = None
+
+        else:
+            new_node = reduce_tree(node.children[0], parent)
+
+    elif node.type == syms.Unit:
+        if (isinstance(node.children[0], pytree.Leaf) and
+            node.children[0].value == '('):
+            #skip parentheses
+            return reduce_tree(node.children[1], parent)
+        if ((isinstance(node.children[0], pytree.Leaf) and
+               node.children[0].value == '[')
+               or
+               (len(node.children)>1 and
+               hasattr(node.children[1], "value") and
+               node.children[1].value == '[')):
+            #skip whole unit if its optional
+            return None
+
+        leaf = True
+        details_node = None
+        alternatives_node = None
+        has_repeater = False
+        repeater_node = None
+        has_variable_name = False
+
+        for child in node.children:
+            if child.type == syms.Details:
+                leaf = False
+                details_node = child
+            elif child.type == syms.Repeater:
+                has_repeater = True
+                repeater_node = child
+            elif child.type == syms.Alternatives:
+                alternatives_node = child
+            if hasattr(child, 'value') and child.value == '=': # variable name
+                has_variable_name = True
+
+        #skip variable name
+        if has_variable_name:
+            #skip variable name, '='
+            name_leaf = node.children[2]
+            if hasattr(name_leaf, 'value') and name_leaf.value == '(':
+                # skip parenthesis
+                name_leaf = node.children[3]
+        else:
+            name_leaf = node.children[0]
+
+        #set node type
+        if name_leaf.type == token_labels.NAME:
+            #(python) non-name or wildcard
+            if name_leaf.value == 'any':
+                new_node = MinNode(type=TYPE_ANY)
+            else:
+                if hasattr(token_labels, name_leaf.value):
+                    new_node = MinNode(type=getattr(token_labels, name_leaf.value))
+                else:
+                    new_node = MinNode(type=getattr(pysyms, name_leaf.value))
+
+        elif name_leaf.type == token_labels.STRING:
+            #(python) name or character; remove the apostrophes from
+            #the string value
+            name = name_leaf.value.strip("'")
+            if name in tokens:
+                new_node = MinNode(type=tokens[name])
+            else:
+                new_node = MinNode(type=token_labels.NAME, name=name)
+        elif name_leaf.type == syms.Alternatives:
+            new_node = reduce_tree(alternatives_node, parent)
+
+        #handle repeaters
+        if has_repeater:
+            if repeater_node.children[0].value == '*':
+                #reduce to None
+                new_node = None
+            elif repeater_node.children[0].value == '+':
+                #reduce to a single occurrence i.e. do nothing
+                pass
+            else:
+                #TODO: handle {min, max} repeaters
+                raise NotImplementedError
+                pass
+
+        #add children
+        if details_node and new_node is not None:
+            for child in details_node.children[1:-1]:
+                #skip '<', '>' markers
+                reduced = reduce_tree(child, new_node)
+                if reduced is not None:
+                    new_node.children.append(reduced)
+    if new_node:
+        new_node.parent = parent
+    return new_node
+
+
+def get_characteristic_subpattern(subpatterns):
+    """Picks the most characteristic from a list of linear patterns
+    Current order used is:
+    names > common_names > common_chars
+    """
+    if not isinstance(subpatterns, list):
+        return subpatterns
+    if len(subpatterns)==1:
+        return subpatterns[0]
+
+    # first pick out the ones containing variable names
+    subpatterns_with_names = []
+    subpatterns_with_common_names = []
+    common_names = ['in', 'for', 'if' , 'not', 'None']
+    subpatterns_with_common_chars = []
+    common_chars = "[]().,:"
+    for subpattern in subpatterns:
+        if any(rec_test(subpattern, lambda x: type(x) is str)):
+            if any(rec_test(subpattern,
+                            lambda x: isinstance(x, str) and x in common_chars)):
+                subpatterns_with_common_chars.append(subpattern)
+            elif any(rec_test(subpattern,
+                              lambda x: isinstance(x, str) and x in common_names)):
+                subpatterns_with_common_names.append(subpattern)
+
+            else:
+                subpatterns_with_names.append(subpattern)
+
+    if subpatterns_with_names:
+        subpatterns = subpatterns_with_names
+    elif subpatterns_with_common_names:
+        subpatterns = subpatterns_with_common_names
+    elif subpatterns_with_common_chars:
+        subpatterns = subpatterns_with_common_chars
+    # of the remaining subpatterns pick out the longest one
+    return max(subpatterns, key=len)
+
+def rec_test(sequence, test_func):
+    """Tests test_func on all items of sequence and items of included
+    sub-iterables"""
+    for x in sequence:
+        if isinstance(x, (list, tuple)):
+            yield from rec_test(x, test_func)
+        else:
+            yield test_func(x)

Lib/lib2to3/fixer_base.py

@@ -0,0 +1,186 @@
+# Copyright 2006 Google, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Base class for fixers (optional, but recommended)."""
+
+# Python imports
+import itertools
+
+# Local imports
+from .patcomp import PatternCompiler
+from . import pygram
+from .fixer_util import does_tree_import
+
+class BaseFix(object):
+
+    """Optional base class for fixers.
+
+    The subclass name must be FixFooBar where FooBar is the result of
+    removing underscores and capitalizing the words of the fix name.
+    For example, the class name for a fixer named 'has_key' should be
+    FixHasKey.
+    """
+
+    PATTERN = None  # Most subclasses should override with a string literal
+    pattern = None  # Compiled pattern, set by compile_pattern()
+    pattern_tree = None # Tree representation of the pattern
+    options = None  # Options object passed to initializer
+    filename = None # The filename (set by set_filename)
+    numbers = itertools.count(1) # For new_name()
+    used_names = set() # A set of all used NAMEs
+    order = "post" # Does the fixer prefer pre- or post-order traversal
+    explicit = False # Is this ignored by refactor.py -f all?
+    run_order = 5   # Fixers will be sorted by run order before execution
+                    # Lower numbers will be run first.
+    _accept_type = None # [Advanced and not public] This tells RefactoringTool
+                        # which node type to accept when there's not a pattern.
+
+    keep_line_order = False # For the bottom matcher: match with the
+                            # original line order
+    BM_compatible = False # Compatibility with the bottom matching
+                          # module; every fixer should set this
+                          # manually
+
+    # Shortcut for access to Python grammar symbols
+    syms = pygram.python_symbols
+
+    def __init__(self, options, log):
+        """Initializer.  Subclass may override.
+
+        Args:
+            options: a dict containing the options passed to RefactoringTool
+            that could be used to customize the fixer through the command line.
+            log: a list to append warnings and other messages to.
+        """
+        self.options = options
+        self.log = log
+        self.compile_pattern()
+
+    def compile_pattern(self):
+        """Compiles self.PATTERN into self.pattern.
+
+        Subclass may override if it doesn't want to use
+        self.{pattern,PATTERN} in .match().
+        """
+        if self.PATTERN is not None:
+            PC = PatternCompiler()
+            self.pattern, self.pattern_tree = PC.compile_pattern(self.PATTERN,
+                                                                 with_tree=True)
+
+    def set_filename(self, filename):
+        """Set the filename.
+
+        The main refactoring tool should call this.
+        """
+        self.filename = filename
+
+    def match(self, node):
+        """Returns match for a given parse tree node.
+
+        Should return a true or false object (not necessarily a bool).
+        It may return a non-empty dict of matching sub-nodes as
+        returned by a matching pattern.
+
+        Subclass may override.
+        """
+        results = {"node": node}
+        return self.pattern.match(node, results) and results
+
+    def transform(self, node, results):
+        """Returns the transformation for a given parse tree node.
+
+        Args:
+          node: the root of the parse tree that matched the fixer.
+          results: a dict mapping symbolic names to part of the match.
+
+        Returns:
+          None, or a node that is a modified copy of the
+          argument node.  The node argument may also be modified in-place to
+          effect the same change.
+
+        Subclass *must* override.
+        """
+        raise NotImplementedError()
+
+    def new_name(self, template="xxx_todo_changeme"):
+        """Return a string suitable for use as an identifier
+
+        The new name is guaranteed not to conflict with other identifiers.
+        """
+        name = template
+        while name in self.used_names:
+            name = template + str(next(self.numbers))
+        self.used_names.add(name)
+        return name
+
+    def log_message(self, message):
+        if self.first_log:
+            self.first_log = False
+            self.log.append("### In file %s ###" % self.filename)
+        self.log.append(message)
+
+    def cannot_convert(self, node, reason=None):
+        """Warn the user that a given chunk of code is not valid Python 3,
+        but that it cannot be converted automatically.
+
+        First argument is the top-level node for the code in question.
+        Optional second argument is why it can't be converted.
+        """
+        lineno = node.get_lineno()
+        for_output = node.clone()
+        for_output.prefix = ""
+        msg = "Line %d: could not convert: %s"
+        self.log_message(msg % (lineno, for_output))
+        if reason:
+            self.log_message(reason)
+
+    def warning(self, node, reason):
+        """Used for warning the user about possible uncertainty in the
+        translation.
+
+        First argument is the top-level node for the code in question.
+        Optional second argument is why it can't be converted.
+        """
+        lineno = node.get_lineno()
+        self.log_message("Line %d: %s" % (lineno, reason))
+
+    def start_tree(self, tree, filename):
+        """Some fixers need to maintain tree-wide state.
+        This method is called once, at the start of tree fix-up.
+
+        tree - the root node of the tree to be processed.
+        filename - the name of the file the tree came from.
+        """
+        self.used_names = tree.used_names
+        self.set_filename(filename)
+        self.numbers = itertools.count(1)
+        self.first_log = True
+
+    def finish_tree(self, tree, filename):
+        """Some fixers need to maintain tree-wide state.
+        This method is called once, at the conclusion of tree fix-up.
+
+        tree - the root node of the tree to be processed.
+        filename - the name of the file the tree came from.
+        """
+        pass
+
+
+class ConditionalFix(BaseFix):
+    """ Base class for fixers which not execute if an import is found. """
+
+    # This is the name of the import which, if found, will cause the test to be skipped
+    skip_on = None
+
+    def start_tree(self, *args):
+        super(ConditionalFix, self).start_tree(*args)
+        self._should_skip = None
+
+    def should_skip(self, node):
+        if self._should_skip is not None:
+            return self._should_skip
+        pkg = self.skip_on.split(".")
+        name = pkg[-1]
+        pkg = ".".join(pkg[:-1])
+        self._should_skip = does_tree_import(pkg, name, node)
+        return self._should_skip

Lib/lib2to3/fixer_util.py

@@ -0,0 +1,453 @@
+"""Utility functions, node construction macros, etc."""
+# Author: Collin Winter
+
+# Local imports
+from .pgen2 import token
+from .pytree import Leaf, Node
+from .pygram import python_symbols as syms
+from . import patcomp
+
+
+###########################################################
+### Common node-construction "macros"
+###########################################################
+
+def KeywordArg(keyword, value):
+    return Node(syms.argument,
+                [keyword, Leaf(token.EQUAL, "="), value])
+
+def LParen():
+    return Leaf(token.LPAR, "(")
+
+def RParen():
+    return Leaf(token.RPAR, ")")
+
+def Assign(target, source):
+    """Build an assignment statement"""
+    if not isinstance(target, list):
+        target = [target]
+    if not isinstance(source, list):
+        source.prefix = " "
+        source = [source]
+
+    return Node(syms.atom,
+                target + [Leaf(token.EQUAL, "=", prefix=" ")] + source)
+
+def Name(name, prefix=None):
+    """Return a NAME leaf"""
+    return Leaf(token.NAME, name, prefix=prefix)
+
+def Attr(obj, attr):
+    """A node tuple for obj.attr"""
+    return [obj, Node(syms.trailer, [Dot(), attr])]
+
+def Comma():
+    """A comma leaf"""
+    return Leaf(token.COMMA, ",")
+
+def Dot():
+    """A period (.) leaf"""
+    return Leaf(token.DOT, ".")
+
+def ArgList(args, lparen=LParen(), rparen=RParen()):
+    """A parenthesised argument list, used by Call()"""
+    node = Node(syms.trailer, [lparen.clone(), rparen.clone()])
+    if args:
+        node.insert_child(1, Node(syms.arglist, args))
+    return node
+
+def Call(func_name, args=None, prefix=None):
+    """A function call"""
+    node = Node(syms.power, [func_name, ArgList(args)])
+    if prefix is not None:
+        node.prefix = prefix
+    return node
+
+def Newline():
+    """A newline literal"""
+    return Leaf(token.NEWLINE, "\n")
+
+def BlankLine():
+    """A blank line"""
+    return Leaf(token.NEWLINE, "")
+
+def Number(n, prefix=None):
+    return Leaf(token.NUMBER, n, prefix=prefix)
+
+def Subscript(index_node):
+    """A numeric or string subscript"""
+    return Node(syms.trailer, [Leaf(token.LBRACE, "["),
+                               index_node,
+                               Leaf(token.RBRACE, "]")])
+
+def String(string, prefix=None):
+    """A string leaf"""
+    return Leaf(token.STRING, string, prefix=prefix)
+
+def ListComp(xp, fp, it, test=None):
+    """A list comprehension of the form [xp for fp in it if test].
+
+    If test is None, the "if test" part is omitted.
+    """
+    xp.prefix = ""
+    fp.prefix = " "
+    it.prefix = " "
+    for_leaf = Leaf(token.NAME, "for")
+    for_leaf.prefix = " "
+    in_leaf = Leaf(token.NAME, "in")
+    in_leaf.prefix = " "
+    inner_args = [for_leaf, fp, in_leaf, it]
+    if test:
+        test.prefix = " "
+        if_leaf = Leaf(token.NAME, "if")
+        if_leaf.prefix = " "
+        inner_args.append(Node(syms.comp_if, [if_leaf, test]))
+    inner = Node(syms.listmaker, [xp, Node(syms.comp_for, inner_args)])
+    return Node(syms.atom,
+                       [Leaf(token.LBRACE, "["),
+                        inner,
+                        Leaf(token.RBRACE, "]")])
+
+def FromImport(package_name, name_leafs):
+    """ Return an import statement in the form:
+        from package import name_leafs"""
+    # XXX: May not handle dotted imports properly (eg, package_name='foo.bar')
+    #assert package_name == '.' or '.' not in package_name, "FromImport has "\
+    #       "not been tested with dotted package names -- use at your own "\
+    #       "peril!"
+
+    for leaf in name_leafs:
+        # Pull the leaves out of their old tree
+        leaf.remove()
+
+    children = [Leaf(token.NAME, "from"),
+                Leaf(token.NAME, package_name, prefix=" "),
+                Leaf(token.NAME, "import", prefix=" "),
+                Node(syms.import_as_names, name_leafs)]
+    imp = Node(syms.import_from, children)
+    return imp
+
+def ImportAndCall(node, results, names):
+    """Returns an import statement and calls a method
+    of the module:
+
+    import module
+    module.name()"""
+    obj = results["obj"].clone()
+    if obj.type == syms.arglist:
+        newarglist = obj.clone()
+    else:
+        newarglist = Node(syms.arglist, [obj.clone()])
+    after = results["after"]
+    if after:
+        after = [n.clone() for n in after]
+    new = Node(syms.power,
+               Attr(Name(names[0]), Name(names[1])) +
+               [Node(syms.trailer,
+                     [results["lpar"].clone(),
+                      newarglist,
+                      results["rpar"].clone()])] + after)
+    new.prefix = node.prefix
+    return new
+
+
+###########################################################
+### Determine whether a node represents a given literal
+###########################################################
+
+def is_tuple(node):
+    """Does the node represent a tuple literal?"""
+    if isinstance(node, Node) and node.children == [LParen(), RParen()]:
+        return True
+    return (isinstance(node, Node)
+            and len(node.children) == 3
+            and isinstance(node.children[0], Leaf)
+            and isinstance(node.children[1], Node)
+            and isinstance(node.children[2], Leaf)
+            and node.children[0].value == "("
+            and node.children[2].value == ")")
+
+def is_list(node):
+    """Does the node represent a list literal?"""
+    return (isinstance(node, Node)
+            and len(node.children) > 1
+            and isinstance(node.children[0], Leaf)
+            and isinstance(node.children[-1], Leaf)
+            and node.children[0].value == "["
+            and node.children[-1].value == "]")
+
+
+###########################################################
+### Misc
+###########################################################
+
+def parenthesize(node):
+    return Node(syms.atom, [LParen(), node, RParen()])
+
+
+consuming_calls = {"sorted", "list", "set", "any", "all", "tuple", "sum",
+                   "min", "max", "enumerate"}
+
+def attr_chain(obj, attr):
+    """Follow an attribute chain.
+
+    If you have a chain of objects where a.foo -> b, b.foo-> c, etc,
+    use this to iterate over all objects in the chain. Iteration is
+    terminated by getattr(x, attr) is None.
+
+    Args:
+        obj: the starting object
+        attr: the name of the chaining attribute
+
+    Yields:
+        Each successive object in the chain.
+    """
+    next = getattr(obj, attr)
+    while next:
+        yield next
+        next = getattr(next, attr)
+
+p0 = """for_stmt< 'for' any 'in' node=any ':' any* >
+        | comp_for< 'for' any 'in' node=any any* >
+     """
+p1 = """
+power<
+    ( 'iter' | 'list' | 'tuple' | 'sorted' | 'set' | 'sum' |
+      'any' | 'all' | 'enumerate' | (any* trailer< '.' 'join' >) )
+    trailer< '(' node=any ')' >
+    any*
+>
+"""
+p2 = """
+power<
+    ( 'sorted' | 'enumerate' )
+    trailer< '(' arglist<node=any any*> ')' >
+    any*
+>
+"""
+pats_built = False
+def in_special_context(node):
+    """ Returns true if node is in an environment where all that is required
+        of it is being iterable (ie, it doesn't matter if it returns a list
+        or an iterator).
+        See test_map_nochange in test_fixers.py for some examples and tests.
+        """
+    global p0, p1, p2, pats_built
+    if not pats_built:
+        p0 = patcomp.compile_pattern(p0)
+        p1 = patcomp.compile_pattern(p1)
+        p2 = patcomp.compile_pattern(p2)
+        pats_built = True
+    patterns = [p0, p1, p2]
+    for pattern, parent in zip(patterns, attr_chain(node, "parent")):
+        results = {}
+        if pattern.match(parent, results) and results["node"] is node:
+            return True
+    return False
+
+def is_probably_builtin(node):
+    """
+    Check that something isn't an attribute or function name etc.
+    """
+    prev = node.prev_sibling
+    if prev is not None and prev.type == token.DOT:
+        # Attribute lookup.
+        return False
+    parent = node.parent
+    if parent.type in (syms.funcdef, syms.classdef):
+        return False
+    if parent.type == syms.expr_stmt and parent.children[0] is node:
+        # Assignment.
+        return False
+    if parent.type == syms.parameters or \
+            (parent.type == syms.typedargslist and (
+            (prev is not None and prev.type == token.COMMA) or
+            parent.children[0] is node
+            )):
+        # The name of an argument.
+        return False
+    return True
+
+def find_indentation(node):
+    """Find the indentation of *node*."""
+    while node is not None:
+        if node.type == syms.suite and len(node.children) > 2:
+            indent = node.children[1]
+            if indent.type == token.INDENT:
+                return indent.value
+        node = node.parent
+    return ""
+
+###########################################################
+### The following functions are to find bindings in a suite
+###########################################################
+
+def make_suite(node):
+    if node.type == syms.suite:
+        return node
+    node = node.clone()
+    parent, node.parent = node.parent, None
+    suite = Node(syms.suite, [node])
+    suite.parent = parent
+    return suite
+
+def find_root(node):
+    """Find the top level namespace."""
+    # Scamper up to the top level namespace
+    while node.type != syms.file_input:
+        node = node.parent
+        if not node:
+            raise ValueError("root found before file_input node was found.")
+    return node
+
+def does_tree_import(package, name, node):
+    """ Returns true if name is imported from package at the
+        top level of the tree which node belongs to.
+        To cover the case of an import like 'import foo', use
+        None for the package and 'foo' for the name. """
+    binding = find_binding(name, find_root(node), package)
+    return bool(binding)
+
+def is_import(node):
+    """Returns true if the node is an import statement."""
+    return node.type in (syms.import_name, syms.import_from)
+
+def touch_import(package, name, node):
+    """ Works like `does_tree_import` but adds an import statement
+        if it was not imported. """
+    def is_import_stmt(node):
+        return (node.type == syms.simple_stmt and node.children and
+                is_import(node.children[0]))
+
+    root = find_root(node)
+
+    if does_tree_import(package, name, root):
+        return
+
+    # figure out where to insert the new import.  First try to find
+    # the first import and then skip to the last one.
+    insert_pos = offset = 0
+    for idx, node in enumerate(root.children):
+        if not is_import_stmt(node):
+            continue
+        for offset, node2 in enumerate(root.children[idx:]):
+            if not is_import_stmt(node2):
+                break
+        insert_pos = idx + offset
+        break
+
+    # if there are no imports where we can insert, find the docstring.
+    # if that also fails, we stick to the beginning of the file
+    if insert_pos == 0:
+        for idx, node in enumerate(root.children):
+            if (node.type == syms.simple_stmt and node.children and
+               node.children[0].type == token.STRING):
+                insert_pos = idx + 1
+                break
+
+    if package is None:
+        import_ = Node(syms.import_name, [
+            Leaf(token.NAME, "import"),
+            Leaf(token.NAME, name, prefix=" ")
+        ])
+    else:
+        import_ = FromImport(package, [Leaf(token.NAME, name, prefix=" ")])
+
+    children = [import_, Newline()]
+    root.insert_child(insert_pos, Node(syms.simple_stmt, children))
+
+
+_def_syms = {syms.classdef, syms.funcdef}
+def find_binding(name, node, package=None):
+    """ Returns the node which binds variable name, otherwise None.
+        If optional argument package is supplied, only imports will
+        be returned.
+        See test cases for examples."""
+    for child in node.children:
+        ret = None
+        if child.type == syms.for_stmt:
+            if _find(name, child.children[1]):
+                return child
+            n = find_binding(name, make_suite(child.children[-1]), package)
+            if n: ret = n
+        elif child.type in (syms.if_stmt, syms.while_stmt):
+            n = find_binding(name, make_suite(child.children[-1]), package)
+            if n: ret = n
+        elif child.type == syms.try_stmt:
+            n = find_binding(name, make_suite(child.children[2]), package)
+            if n:
+                ret = n
+            else:
+                for i, kid in enumerate(child.children[3:]):
+                    if kid.type == token.COLON and kid.value == ":":
+                        # i+3 is the colon, i+4 is the suite
+                        n = find_binding(name, make_suite(child.children[i+4]), package)
+                        if n: ret = n
+        elif child.type in _def_syms and child.children[1].value == name:
+            ret = child
+        elif _is_import_binding(child, name, package):
+            ret = child
+        elif child.type == syms.simple_stmt:
+            ret = find_binding(name, child, package)
+        elif child.type == syms.expr_stmt:
+            if _find(name, child.children[0]):
+                ret = child
+
+        if ret:
+            if not package:
+                return ret
+            if is_import(ret):
+                return ret
+    return None
+
+_block_syms = {syms.funcdef, syms.classdef, syms.trailer}
+def _find(name, node):
+    nodes = [node]
+    while nodes:
+        node = nodes.pop()
+        if node.type > 256 and node.type not in _block_syms:
+            nodes.extend(node.children)
+        elif node.type == token.NAME and node.value == name:
+            return node
+    return None
+
+def _is_import_binding(node, name, package=None):
+    """ Will reuturn node if node will import name, or node
+        will import * from package.  None is returned otherwise.
+        See test cases for examples. """
+
+    if node.type == syms.import_name and not package:
+        imp = node.children[1]
+        if imp.type == syms.dotted_as_names:
+            for child in imp.children:
+                if child.type == syms.dotted_as_name:
+                    if child.children[2].value == name:
+                        return node
+                elif child.type == token.NAME and child.value == name:
+                    return node
+        elif imp.type == syms.dotted_as_name:
+            last = imp.children[-1]
+            if last.type == token.NAME and last.value == name:
+                return node
+        elif imp.type == token.NAME and imp.value == name:
+            return node
+    elif node.type == syms.import_from:
+        # str(...) is used to make life easier here, because
+        # from a.b import parses to ['import', ['a', '.', 'b'], ...]
+        if package and str(node.children[1]).strip() != package:
+            return None
+        n = node.children[3]
+        if package and _find("as", n):
+            # See test_from_import_as for explanation
+            return None
+        elif n.type == syms.import_as_names and _find(name, n):
+            return node
+        elif n.type == syms.import_as_name:
+            child = n.children[2]
+            if child.type == token.NAME and child.value == name:
+                return node
+        elif n.type == token.NAME and n.value == name:
+            return node
+        elif package and n.type == token.STAR:
+            return node
+    return None

Lib/lib2to3/fixes/__init__.py

@@ -0,0 +1 @@
+# Dummy file to make this directory a package.

Lib/lib2to3/fixes/fix_apply.py

@@ -0,0 +1,70 @@
+# Copyright 2006 Google, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Fixer for apply().
+
+This converts apply(func, v, k) into (func)(*v, **k)."""
+
+# Local imports
+from .. import pytree
+from ..pgen2 import token
+from .. import fixer_base
+from ..fixer_util import Call, Comma, parenthesize
+
+class FixApply(fixer_base.BaseFix):
+    BM_compatible = True
+
+    PATTERN = """
+    power< 'apply'
+        trailer<
+            '('
+            arglist<
+                (not argument<NAME '=' any>) func=any ','
+                (not argument<NAME '=' any>) args=any [','
+                (not argument<NAME '=' any>) kwds=any] [',']
+            >
+            ')'
+        >
+    >
+    """
+
+    def transform(self, node, results):
+        syms = self.syms
+        assert results
+        func = results["func"]
+        args = results["args"]
+        kwds = results.get("kwds")
+        # I feel like we should be able to express this logic in the
+        # PATTERN above but I don't know how to do it so...
+        if args:
+            if args.type == self.syms.star_expr:
+                return  # Make no change.
+            if (args.type == self.syms.argument and
+                args.children[0].value == '**'):
+                return  # Make no change.
+        if kwds and (kwds.type == self.syms.argument and
+                     kwds.children[0].value == '**'):
+            return  # Make no change.
+        prefix = node.prefix
+        func = func.clone()
+        if (func.type not in (token.NAME, syms.atom) and
+            (func.type != syms.power or
+             func.children[-2].type == token.DOUBLESTAR)):
+            # Need to parenthesize
+            func = parenthesize(func)
+        func.prefix = ""
+        args = args.clone()
+        args.prefix = ""
+        if kwds is not None:
+            kwds = kwds.clone()
+            kwds.prefix = ""
+        l_newargs = [pytree.Leaf(token.STAR, "*"), args]
+        if kwds is not None:
+            l_newargs.extend([Comma(),
+                              pytree.Leaf(token.DOUBLESTAR, "**"),
+                              kwds])
+            l_newargs[-2].prefix = " " # that's the ** token
+        # XXX Sometimes we could be cleverer, e.g. apply(f, (x, y) + t)
+        # can be translated into f(x, y, *t) instead of f(*(x, y) + t)
+        #new = pytree.Node(syms.power, (func, ArgList(l_newargs)))
+        return Call(func, l_newargs, prefix=prefix)

Lib/lib2to3/fixes/fix_asserts.py

@@ -0,0 +1,34 @@
+"""Fixer that replaces deprecated unittest method names."""
+
+# Author: Ezio Melotti
+
+from ..fixer_base import BaseFix
+from ..fixer_util import Name
+
+NAMES = dict(
+    assert_="assertTrue",
+    assertEquals="assertEqual",
+    assertNotEquals="assertNotEqual",
+    assertAlmostEquals="assertAlmostEqual",
+    assertNotAlmostEquals="assertNotAlmostEqual",
+    assertRegexpMatches="assertRegex",
+    assertRaisesRegexp="assertRaisesRegex",
+    failUnlessEqual="assertEqual",
+    failIfEqual="assertNotEqual",
+    failUnlessAlmostEqual="assertAlmostEqual",
+    failIfAlmostEqual="assertNotAlmostEqual",
+    failUnless="assertTrue",
+    failUnlessRaises="assertRaises",
+    failIf="assertFalse",
+)
+
+
+class FixAsserts(BaseFix):
+
+    PATTERN = """
+              power< any+ trailer< '.' meth=(%s)> any* >
+              """ % '|'.join(map(repr, NAMES))
+
+    def transform(self, node, results):
+        name = results["meth"][0]
+        name.replace(Name(NAMES[str(name)], prefix=name.prefix))

Lib/lib2to3/fixes/fix_basestring.py

@@ -0,0 +1,14 @@
+"""Fixer for basestring -> str."""
+# Author: Christian Heimes
+
+# Local imports
+from .. import fixer_base
+from ..fixer_util import Name
+
+class FixBasestring(fixer_base.BaseFix):
+    BM_compatible = True
+
+    PATTERN = "'basestring'"
+
+    def transform(self, node, results):
+        return Name("str", prefix=node.prefix)

Lib/lib2to3/fixes/fix_buffer.py

@@ -0,0 +1,22 @@
+# Copyright 2007 Google, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Fixer that changes buffer(...) into memoryview(...)."""
+
+# Local imports
+from .. import fixer_base
+from ..fixer_util import Name
+
+
+class FixBuffer(fixer_base.BaseFix):
+    BM_compatible = True
+
+    explicit = True # The user must ask for this fixer
+
+    PATTERN = """
+              power< name='buffer' trailer< '(' [any] ')' > any* >
+              """
+
+    def transform(self, node, results):
+        name = results["name"]
+        name.replace(Name("memoryview", prefix=name.prefix))

Lib/lib2to3/fixes/fix_dict.py

@@ -0,0 +1,106 @@
+# Copyright 2007 Google, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Fixer for dict methods.
+
+d.keys() -> list(d.keys())
+d.items() -> list(d.items())
+d.values() -> list(d.values())
+
+d.iterkeys() -> iter(d.keys())
+d.iteritems() -> iter(d.items())
+d.itervalues() -> iter(d.values())
+
+d.viewkeys() -> d.keys()
+d.viewitems() -> d.items()
+d.viewvalues() -> d.values()
+
+Except in certain very specific contexts: the iter() can be dropped
+when the context is list(), sorted(), iter() or for...in; the list()
+can be dropped when the context is list() or sorted() (but not iter()
+or for...in!). Special contexts that apply to both: list(), sorted(), tuple()
+set(), any(), all(), sum().
+
+Note: iter(d.keys()) could be written as iter(d) but since the
+original d.iterkeys() was also redundant we don't fix this.  And there
+are (rare) contexts where it makes a difference (e.g. when passing it
+as an argument to a function that introspects the argument).
+"""
+
+# Local imports
+from .. import pytree
+from .. import patcomp
+from .. import fixer_base
+from ..fixer_util import Name, Call, Dot
+from .. import fixer_util
+
+
+iter_exempt = fixer_util.consuming_calls | {"iter"}
+
+
+class FixDict(fixer_base.BaseFix):
+    BM_compatible = True
+
+    PATTERN = """
+    power< head=any+
+         trailer< '.' method=('keys'|'items'|'values'|
+                              'iterkeys'|'iteritems'|'itervalues'|
+                              'viewkeys'|'viewitems'|'viewvalues') >
+         parens=trailer< '(' ')' >
+         tail=any*
+    >
+    """
+
+    def transform(self, node, results):
+        head = results["head"]
+        method = results["method"][0] # Extract node for method name
+        tail = results["tail"]
+        syms = self.syms
+        method_name = method.value
+        isiter = method_name.startswith("iter")
+        isview = method_name.startswith("view")
+        if isiter or isview:
+            method_name = method_name[4:]
+        assert method_name in ("keys", "items", "values"), repr(method)
+        head = [n.clone() for n in head]
+        tail = [n.clone() for n in tail]
+        special = not tail and self.in_special_context(node, isiter)
+        args = head + [pytree.Node(syms.trailer,
+                                   [Dot(),
+                                    Name(method_name,
+                                         prefix=method.prefix)]),
+                       results["parens"].clone()]
+        new = pytree.Node(syms.power, args)
+        if not (special or isview):
+            new.prefix = ""
+            new = Call(Name("iter" if isiter else "list"), [new])
+        if tail:
+            new = pytree.Node(syms.power, [new] + tail)
+        new.prefix = node.prefix
+        return new
+
+    P1 = "power< func=NAME trailer< '(' node=any ')' > any* >"
+    p1 = patcomp.compile_pattern(P1)
+
+    P2 = """for_stmt< 'for' any 'in' node=any ':' any* >
+            | comp_for< 'for' any 'in' node=any any* >
+         """
+    p2 = patcomp.compile_pattern(P2)
+
+    def in_special_context(self, node, isiter):
+        if node.parent is None:
+            return False
+        results = {}
+        if (node.parent.parent is not None and
+               self.p1.match(node.parent.parent, results) and
+               results["node"] is node):
+            if isiter:
+                # iter(d.iterkeys()) -> iter(d.keys()), etc.
+                return results["func"].value in iter_exempt
+            else:
+                # list(d.keys()) -> list(d.keys()), etc.
+                return results["func"].value in fixer_util.consuming_calls
+        if not isiter:
+            return False
+        # for ... in d.iterkeys() -> for ... in d.keys(), etc.
+        return self.p2.match(node.parent, results) and results["node"] is node

Lib/lib2to3/fixes/fix_except.py

@@ -0,0 +1,93 @@
+"""Fixer for except statements with named exceptions.
+
+The following cases will be converted:
+
+- "except E, T:" where T is a name:
+
+    except E as T:
+
+- "except E, T:" where T is not a name, tuple or list:
+
+        except E as t:
+            T = t
+
+    This is done because the target of an "except" clause must be a
+    name.
+
+- "except E, T:" where T is a tuple or list literal:
+
+        except E as t:
+            T = t.args
+"""
+# Author: Collin Winter
+
+# Local imports
+from .. import pytree
+from ..pgen2 import token
+from .. import fixer_base
+from ..fixer_util import Assign, Attr, Name, is_tuple, is_list, syms
+
+def find_excepts(nodes):
+    for i, n in enumerate(nodes):
+        if n.type == syms.except_clause:
+            if n.children[0].value == 'except':
+                yield (n, nodes[i+2])
+
+class FixExcept(fixer_base.BaseFix):
+    BM_compatible = True
+
+    PATTERN = """
+    try_stmt< 'try' ':' (simple_stmt | suite)
+                  cleanup=(except_clause ':' (simple_stmt | suite))+
+                  tail=(['except' ':' (simple_stmt | suite)]
+                        ['else' ':' (simple_stmt | suite)]
+                        ['finally' ':' (simple_stmt | suite)]) >
+    """
+
+    def transform(self, node, results):
+        syms = self.syms
+
+        tail = [n.clone() for n in results["tail"]]
+
+        try_cleanup = [ch.clone() for ch in results["cleanup"]]
+        for except_clause, e_suite in find_excepts(try_cleanup):
+            if len(except_clause.children) == 4:
+                (E, comma, N) = except_clause.children[1:4]
+                comma.replace(Name("as", prefix=" "))
+
+                if N.type != token.NAME:
+                    # Generate a new N for the except clause
+                    new_N = Name(self.new_name(), prefix=" ")
+                    target = N.clone()
+                    target.prefix = ""
+                    N.replace(new_N)
+                    new_N = new_N.clone()
+
+                    # Insert "old_N = new_N" as the first statement in
+                    #  the except body. This loop skips leading whitespace
+                    #  and indents
+                    #TODO(cwinter) suite-cleanup
+                    suite_stmts = e_suite.children
+                    for i, stmt in enumerate(suite_stmts):
+                        if isinstance(stmt, pytree.Node):
+                            break
+
+                    # The assignment is different if old_N is a tuple or list
+                    # In that case, the assignment is old_N = new_N.args
+                    if is_tuple(N) or is_list(N):
+                        assign = Assign(target, Attr(new_N, Name('args')))
+                    else:
+                        assign = Assign(target, new_N)
+
+                    #TODO(cwinter) stopgap until children becomes a smart list
+                    for child in reversed(suite_stmts[:i]):
+                        e_suite.insert_child(0, child)
+                    e_suite.insert_child(i, assign)
+                elif N.prefix == "":
+                    # No space after a comma is legal; no space after "as",
+                    # not so much.
+                    N.prefix = " "
+
+        #TODO(cwinter) fix this when children becomes a smart list
+        children = [c.clone() for c in node.children[:3]] + try_cleanup + tail
+        return pytree.Node(node.type, children)

Lib/lib2to3/fixes/fix_exec.py

@@ -0,0 +1,39 @@
+# Copyright 2006 Google, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Fixer for exec.
+
+This converts usages of the exec statement into calls to a built-in
+exec() function.
+
+exec code in ns1, ns2 -> exec(code, ns1, ns2)
+"""
+
+# Local imports
+from .. import fixer_base
+from ..fixer_util import Comma, Name, Call
+
+
+class FixExec(fixer_base.BaseFix):
+    BM_compatible = True
+
+    PATTERN = """
+    exec_stmt< 'exec' a=any 'in' b=any [',' c=any] >
+    |
+    exec_stmt< 'exec' (not atom<'(' [any] ')'>) a=any >
+    """
+
+    def transform(self, node, results):
+        assert results
+        syms = self.syms
+        a = results["a"]
+        b = results.get("b")
+        c = results.get("c")
+        args = [a.clone()]
+        args[0].prefix = ""
+        if b is not None:
+            args.extend([Comma(), b.clone()])
+        if c is not None:
+            args.extend([Comma(), c.clone()])
+
+        return Call(Name("exec"), args, prefix=node.prefix)

Lib/lib2to3/fixes/fix_execfile.py

@@ -0,0 +1,53 @@
+# Copyright 2006 Google, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Fixer for execfile.
+
+This converts usages of the execfile function into calls to the built-in
+exec() function.
+"""
+
+from .. import fixer_base
+from ..fixer_util import (Comma, Name, Call, LParen, RParen, Dot, Node,
+                          ArgList, String, syms)
+
+
+class FixExecfile(fixer_base.BaseFix):
+    BM_compatible = True
+
+    PATTERN = """
+    power< 'execfile' trailer< '(' arglist< filename=any [',' globals=any [',' locals=any ] ] > ')' > >
+    |
+    power< 'execfile' trailer< '(' filename=any ')' > >
+    """
+
+    def transform(self, node, results):
+        assert results
+        filename = results["filename"]
+        globals = results.get("globals")
+        locals = results.get("locals")
+
+        # Copy over the prefix from the right parentheses end of the execfile
+        # call.
+        execfile_paren = node.children[-1].children[-1].clone()
+        # Construct open().read().
+        open_args = ArgList([filename.clone(), Comma(), String('"rb"', ' ')],
+                            rparen=execfile_paren)
+        open_call = Node(syms.power, [Name("open"), open_args])
+        read = [Node(syms.trailer, [Dot(), Name('read')]),
+                Node(syms.trailer, [LParen(), RParen()])]
+        open_expr = [open_call] + read
+        # Wrap the open call in a compile call. This is so the filename will be
+        # preserved in the execed code.
+        filename_arg = filename.clone()
+        filename_arg.prefix = " "
+        exec_str = String("'exec'", " ")
+        compile_args = open_expr + [Comma(), filename_arg, Comma(), exec_str]
+        compile_call = Call(Name("compile"), compile_args, "")
+        # Finally, replace the execfile call with an exec call.
+        args = [compile_call]
+        if globals is not None:
+            args.extend([Comma(), globals.clone()])
+        if locals is not None:
+            args.extend([Comma(), locals.clone()])
+        return Call(Name("exec"), args, prefix=node.prefix)

Lib/lib2to3/fixes/fix_exitfunc.py

@@ -0,0 +1,72 @@
+"""
+Convert use of sys.exitfunc to use the atexit module.
+"""
+
+# Author: Benjamin Peterson
+
+from lib2to3 import pytree, fixer_base
+from lib2to3.fixer_util import Name, Attr, Call, Comma, Newline, syms
+
+
+class FixExitfunc(fixer_base.BaseFix):
+    keep_line_order = True
+    BM_compatible = True
+
+    PATTERN = """
+              (
+                  sys_import=import_name<'import'
+                      ('sys'
+                      |
+                      dotted_as_names< (any ',')* 'sys' (',' any)* >
+                      )
+                  >
+              |
+                  expr_stmt<
+                      power< 'sys' trailer< '.' 'exitfunc' > >
+                  '=' func=any >
+              )
+              """
+
+    def __init__(self, *args):
+        super(FixExitfunc, self).__init__(*args)
+
+    def start_tree(self, tree, filename):
+        super(FixExitfunc, self).start_tree(tree, filename)
+        self.sys_import = None
+
+    def transform(self, node, results):
+        # First, find the sys import. We'll just hope it's global scope.
+        if "sys_import" in results:
+            if self.sys_import is None:
+                self.sys_import = results["sys_import"]
+            return
+
+        func = results["func"].clone()
+        func.prefix = ""
+        register = pytree.Node(syms.power,
+                               Attr(Name("atexit"), Name("register"))
+                               )
+        call = Call(register, [func], node.prefix)
+        node.replace(call)
+
+        if self.sys_import is None:
+            # That's interesting.
+            self.warning(node, "Can't find sys import; Please add an atexit "
+                             "import at the top of your file.")
+            return
+
+        # Now add an atexit import after the sys import.
+        names = self.sys_import.children[1]
+        if names.type == syms.dotted_as_names:
+            names.append_child(Comma())
+            names.append_child(Name("atexit", " "))
+        else:
+            containing_stmt = self.sys_import.parent
+            position = containing_stmt.children.index(self.sys_import)
+            stmt_container = containing_stmt.parent
+            new_import = pytree.Node(syms.import_name,
+                              [Name("import"), Name("atexit", " ")]
+                              )
+            new = pytree.Node(syms.simple_stmt, [new_import])
+            containing_stmt.insert_child(position + 1, Newline())
+            containing_stmt.insert_child(position + 2, new)

Lib/lib2to3/fixes/fix_filter.py

@@ -0,0 +1,90 @@
+# Copyright 2007 Google, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Fixer that changes filter(F, X) into list(filter(F, X)).
+
+We avoid the transformation if the filter() call is directly contained
+in iter(<>), list(<>), tuple(<>), sorted(<>), ...join(<>), or
+for V in <>:.
+
+NOTE: This is still not correct if the original code was depending on
+filter(F, X) to return a string if X is a string and a tuple if X is a
+tuple.  That would require type inference, which we don't do.  Let
+Python 2.6 figure it out.
+"""
+
+# Local imports
+from .. import fixer_base
+from ..pytree import Node
+from ..pygram import python_symbols as syms
+from ..fixer_util import Name, ArgList, ListComp, in_special_context
+
+
+class FixFilter(fixer_base.ConditionalFix):
+    BM_compatible = True
+
+    PATTERN = """
+    filter_lambda=power<
+        'filter'
+        trailer<
+            '('
+            arglist<
+                lambdef< 'lambda'
+                         (fp=NAME | vfpdef< '(' fp=NAME ')'> ) ':' xp=any
+                >
+                ','
+                it=any
+            >
+            ')'
+        >
+        [extra_trailers=trailer*]
+    >
+    |
+    power<
+        'filter'
+        trailer< '(' arglist< none='None' ',' seq=any > ')' >
+        [extra_trailers=trailer*]
+    >
+    |
+    power<
+        'filter'
+        args=trailer< '(' [any] ')' >
+        [extra_trailers=trailer*]
+    >
+    """
+
+    skip_on = "future_builtins.filter"
+
+    def transform(self, node, results):
+        if self.should_skip(node):
+            return
+
+        trailers = []
+        if 'extra_trailers' in results:
+            for t in results['extra_trailers']:
+                trailers.append(t.clone())
+
+        if "filter_lambda" in results:
+            new = ListComp(results.get("fp").clone(),
+                           results.get("fp").clone(),
+                           results.get("it").clone(),
+                           results.get("xp").clone())
+            new = Node(syms.power, [new] + trailers, prefix="")
+
+        elif "none" in results:
+            new = ListComp(Name("_f"),
+                           Name("_f"),
+                           results["seq"].clone(),
+                           Name("_f"))
+            new = Node(syms.power, [new] + trailers, prefix="")
+
+        else:
+            if in_special_context(node):
+                return None
+
+            args = results['args'].clone()
+            new = Node(syms.power, [Name("filter"), args], prefix="")
+            new = Node(syms.power, [Name("list"), ArgList([new])] + trailers)
+            new.prefix = ""
+        new.prefix = node.prefix
+        return new

Lib/lib2to3/fixes/fix_funcattrs.py

@@ -0,0 +1,21 @@
+"""Fix function attribute names (f.func_x -> f.__x__)."""
+# Author: Collin Winter
+
+# Local imports
+from .. import fixer_base
+from ..fixer_util import Name
+
+
+class FixFuncattrs(fixer_base.BaseFix):
+    BM_compatible = True
+
+    PATTERN = """
+    power< any+ trailer< '.' attr=('func_closure' | 'func_doc' | 'func_globals'
+                                  | 'func_name' | 'func_defaults' | 'func_code'
+                                  | 'func_dict') > any* >
+    """
+
+    def transform(self, node, results):
+        attr = results["attr"][0]
+        attr.replace(Name(("__%s__" % attr.value[5:]),
+                          prefix=attr.prefix))

Lib/lib2to3/fixes/fix_future.py

@@ -0,0 +1,22 @@
+"""Remove __future__ imports
+
+from __future__ import foo is replaced with an empty line.
+"""
+# Author: Christian Heimes
+
+# Local imports
+from .. import fixer_base
+from ..fixer_util import BlankLine
+
+class FixFuture(fixer_base.BaseFix):
+    BM_compatible = True
+
+    PATTERN = """import_from< 'from' module_name="__future__" 'import' any >"""
+
+    # This should be run last -- some things check for the import
+    run_order = 10
+
+    def transform(self, node, results):
+        new = BlankLine()
+        new.prefix = node.prefix
+        return new

Lib/lib2to3/fixes/fix_getcwdu.py

@@ -0,0 +1,19 @@
+"""
+Fixer that changes os.getcwdu() to os.getcwd().
+"""
+# Author: Victor Stinner
+
+# Local imports
+from .. import fixer_base
+from ..fixer_util import Name
+
+class FixGetcwdu(fixer_base.BaseFix):
+    BM_compatible = True
+
+    PATTERN = """
+              power< 'os' trailer< dot='.' name='getcwdu' > any* >
+              """
+
+    def transform(self, node, results):
+        name = results["name"]
+        name.replace(Name("getcwd", prefix=name.prefix))

Lib/lib2to3/fixes/fix_has_key.py

@@ -0,0 +1,109 @@
+# Copyright 2006 Google, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Fixer for has_key().
+
+Calls to .has_key() methods are expressed in terms of the 'in'
+operator:
+
+    d.has_key(k) -> k in d
+
+CAVEATS:
+1) While the primary target of this fixer is dict.has_key(), the
+   fixer will change any has_key() method call, regardless of its
+   class.
+
+2) Cases like this will not be converted:
+
+    m = d.has_key
+    if m(k):
+        ...
+
+   Only *calls* to has_key() are converted. While it is possible to
+   convert the above to something like
+
+    m = d.__contains__
+    if m(k):
+        ...
+
+   this is currently not done.
+"""
+
+# Local imports
+from .. import pytree
+from .. import fixer_base
+from ..fixer_util import Name, parenthesize
+
+
+class FixHasKey(fixer_base.BaseFix):
+    BM_compatible = True
+
+    PATTERN = """
+    anchor=power<
+        before=any+
+        trailer< '.' 'has_key' >
+        trailer<
+            '('
+            ( not(arglist | argument<any '=' any>) arg=any
+            | arglist<(not argument<any '=' any>) arg=any ','>
+            )
+            ')'
+        >
+        after=any*
+    >
+    |
+    negation=not_test<
+        'not'
+        anchor=power<
+            before=any+
+            trailer< '.' 'has_key' >
+            trailer<
+                '('
+                ( not(arglist | argument<any '=' any>) arg=any
+                | arglist<(not argument<any '=' any>) arg=any ','>
+                )
+                ')'
+            >
+        >
+    >
+    """
+
+    def transform(self, node, results):
+        assert results
+        syms = self.syms
+        if (node.parent.type == syms.not_test and
+            self.pattern.match(node.parent)):
+            # Don't transform a node matching the first alternative of the
+            # pattern when its parent matches the second alternative
+            return None
+        negation = results.get("negation")
+        anchor = results["anchor"]
+        prefix = node.prefix
+        before = [n.clone() for n in results["before"]]
+        arg = results["arg"].clone()
+        after = results.get("after")
+        if after:
+            after = [n.clone() for n in after]
+        if arg.type in (syms.comparison, syms.not_test, syms.and_test,
+                        syms.or_test, syms.test, syms.lambdef, syms.argument):
+            arg = parenthesize(arg)
+        if len(before) == 1:
+            before = before[0]
+        else:
+            before = pytree.Node(syms.power, before)
+        before.prefix = " "
+        n_op = Name("in", prefix=" ")
+        if negation:
+            n_not = Name("not", prefix=" ")
+            n_op = pytree.Node(syms.comp_op, (n_not, n_op))
+        new = pytree.Node(syms.comparison, (arg, n_op, before))
+        if after:
+            new = parenthesize(new)
+            new = pytree.Node(syms.power, (new,) + tuple(after))
+        if node.parent.type in (syms.comparison, syms.expr, syms.xor_expr,
+                                syms.and_expr, syms.shift_expr,
+                                syms.arith_expr, syms.term,
+                                syms.factor, syms.power):
+            new = parenthesize(new)
+        new.prefix = prefix
+        return new

Lib/lib2to3/fixes/fix_idioms.py

@@ -0,0 +1,152 @@
+"""Adjust some old Python 2 idioms to their modern counterparts.
+
+* Change some type comparisons to isinstance() calls:
+    type(x) == T -> isinstance(x, T)
+    type(x) is T -> isinstance(x, T)
+    type(x) != T -> not isinstance(x, T)
+    type(x) is not T -> not isinstance(x, T)
+
+* Change "while 1:" into "while True:".
+
+* Change both
+
+    v = list(EXPR)
+    v.sort()
+    foo(v)
+
+and the more general
+
+    v = EXPR
+    v.sort()
+    foo(v)
+
+into
+
+    v = sorted(EXPR)
+    foo(v)
+"""
+# Author: Jacques Frechet, Collin Winter
+
+# Local imports
+from .. import fixer_base
+from ..fixer_util import Call, Comma, Name, Node, BlankLine, syms
+
+CMP = "(n='!=' | '==' | 'is' | n=comp_op< 'is' 'not' >)"
+TYPE = "power< 'type' trailer< '(' x=any ')' > >"
+
+class FixIdioms(fixer_base.BaseFix):
+    explicit = True # The user must ask for this fixer
+
+    PATTERN = r"""
+        isinstance=comparison< %s %s T=any >
+        |
+        isinstance=comparison< T=any %s %s >
+        |
+        while_stmt< 'while' while='1' ':' any+ >
+        |
+        sorted=any<
+            any*
+            simple_stmt<
+              expr_stmt< id1=any '='
+                         power< list='list' trailer< '(' (not arglist<any+>) any ')' > >
+              >
+              '\n'
+            >
+            sort=
+            simple_stmt<
+              power< id2=any
+                     trailer< '.' 'sort' > trailer< '(' ')' >
+              >
+              '\n'
+            >
+            next=any*
+        >
+        |
+        sorted=any<
+            any*
+            simple_stmt< expr_stmt< id1=any '=' expr=any > '\n' >
+            sort=
+            simple_stmt<
+              power< id2=any
+                     trailer< '.' 'sort' > trailer< '(' ')' >
+              >
+              '\n'
+            >
+            next=any*
+        >
+    """ % (TYPE, CMP, CMP, TYPE)
+
+    def match(self, node):
+        r = super(FixIdioms, self).match(node)
+        # If we've matched one of the sort/sorted subpatterns above, we
+        # want to reject matches where the initial assignment and the
+        # subsequent .sort() call involve different identifiers.
+        if r and "sorted" in r:
+            if r["id1"] == r["id2"]:
+                return r
+            return None
+        return r
+
+    def transform(self, node, results):
+        if "isinstance" in results:
+            return self.transform_isinstance(node, results)
+        elif "while" in results:
+            return self.transform_while(node, results)
+        elif "sorted" in results:
+            return self.transform_sort(node, results)
+        else:
+            raise RuntimeError("Invalid match")
+
+    def transform_isinstance(self, node, results):
+        x = results["x"].clone() # The thing inside of type()
+        T = results["T"].clone() # The type being compared against
+        x.prefix = ""
+        T.prefix = " "
+        test = Call(Name("isinstance"), [x, Comma(), T])
+        if "n" in results:
+            test.prefix = " "
+            test = Node(syms.not_test, [Name("not"), test])
+        test.prefix = node.prefix
+        return test
+
+    def transform_while(self, node, results):
+        one = results["while"]
+        one.replace(Name("True", prefix=one.prefix))
+
+    def transform_sort(self, node, results):
+        sort_stmt = results["sort"]
+        next_stmt = results["next"]
+        list_call = results.get("list")
+        simple_expr = results.get("expr")
+
+        if list_call:
+            list_call.replace(Name("sorted", prefix=list_call.prefix))
+        elif simple_expr:
+            new = simple_expr.clone()
+            new.prefix = ""
+            simple_expr.replace(Call(Name("sorted"), [new],
+                                     prefix=simple_expr.prefix))
+        else:
+            raise RuntimeError("should not have reached here")
+        sort_stmt.remove()
+
+        btwn = sort_stmt.prefix
+        # Keep any prefix lines between the sort_stmt and the list_call and
+        # shove them right after the sorted() call.
+        if "\n" in btwn:
+            if next_stmt:
+                # The new prefix should be everything from the sort_stmt's
+                # prefix up to the last newline, then the old prefix after a new
+                # line.
+                prefix_lines = (btwn.rpartition("\n")[0], next_stmt[0].prefix)
+                next_stmt[0].prefix = "\n".join(prefix_lines)
+            else:
+                assert list_call.parent
+                assert list_call.next_sibling is None
+                # Put a blank line after list_call and set its prefix.
+                end_line = BlankLine()
+                list_call.parent.append_child(end_line)
+                assert list_call.next_sibling is end_line
+                # The new prefix should be everything up to the first new line
+                # of sort_stmt's prefix.
+                end_line.prefix = btwn.rpartition("\n")[0]

Lib/lib2to3/fixes/fix_import.py

@@ -0,0 +1,99 @@
+"""Fixer for import statements.
+If spam is being imported from the local directory, this import:
+    from spam import eggs
+Becomes:
+    from .spam import eggs
+
+And this import:
+    import spam
+Becomes:
+    from . import spam
+"""
+
+# Local imports
+from .. import fixer_base
+from os.path import dirname, join, exists, sep
+from ..fixer_util import FromImport, syms, token
+
+
+def traverse_imports(names):
+    """
+    Walks over all the names imported in a dotted_as_names node.
+    """
+    pending = [names]
+    while pending:
+        node = pending.pop()
+        if node.type == token.NAME:
+            yield node.value
+        elif node.type == syms.dotted_name:
+            yield "".join([ch.value for ch in node.children])
+        elif node.type == syms.dotted_as_name:
+            pending.append(node.children[0])
+        elif node.type == syms.dotted_as_names:
+            pending.extend(node.children[::-2])
+        else:
+            raise AssertionError("unknown node type")
+
+
+class FixImport(fixer_base.BaseFix):
+    BM_compatible = True
+
+    PATTERN = """
+    import_from< 'from' imp=any 'import' ['('] any [')'] >
+    |
+    import_name< 'import' imp=any >
+    """
+
+    def start_tree(self, tree, name):
+        super(FixImport, self).start_tree(tree, name)
+        self.skip = "absolute_import" in tree.future_features
+
+    def transform(self, node, results):
+        if self.skip:
+            return
+        imp = results['imp']
+
+        if node.type == syms.import_from:
+            # Some imps are top-level (eg: 'import ham')
+            # some are first level (eg: 'import ham.eggs')
+            # some are third level (eg: 'import ham.eggs as spam')
+            # Hence, the loop
+            while not hasattr(imp, 'value'):
+                imp = imp.children[0]
+            if self.probably_a_local_import(imp.value):
+                imp.value = "." + imp.value
+                imp.changed()
+        else:
+            have_local = False
+            have_absolute = False
+            for mod_name in traverse_imports(imp):
+                if self.probably_a_local_import(mod_name):
+                    have_local = True
+                else:
+                    have_absolute = True
+            if have_absolute:
+                if have_local:
+                    # We won't handle both sibling and absolute imports in the
+                    # same statement at the moment.
+                    self.warning(node, "absolute and local imports together")
+                return
+
+            new = FromImport(".", [imp])
+            new.prefix = node.prefix
+            return new
+
+    def probably_a_local_import(self, imp_name):
+        if imp_name.startswith("."):
+            # Relative imports are certainly not local imports.
+            return False
+        imp_name = imp_name.split(".", 1)[0]
+        base_path = dirname(self.filename)
+        base_path = join(base_path, imp_name)
+        # If there is no __init__.py next to the file its not in a package
+        # so can't be a relative import.
+        if not exists(join(dirname(base_path), "__init__.py")):
+            return False
+        for ext in [".py", sep, ".pyc", ".so", ".sl", ".pyd"]:
+            if exists(base_path + ext):
+                return True
+        return False

Lib/lib2to3/fixes/fix_imports.py

@@ -0,0 +1,145 @@
+"""Fix incompatible imports and module references."""
+# Authors: Collin Winter, Nick Edds
+
+# Local imports
+from .. import fixer_base
+from ..fixer_util import Name, attr_chain
+
+MAPPING = {'StringIO':  'io',
+           'cStringIO': 'io',
+           'cPickle': 'pickle',
+           '__builtin__' : 'builtins',
+           'copy_reg': 'copyreg',
+           'Queue': 'queue',
+           'SocketServer': 'socketserver',
+           'ConfigParser': 'configparser',
+           'repr': 'reprlib',
+           'FileDialog': 'tkinter.filedialog',
+           'tkFileDialog': 'tkinter.filedialog',
+           'SimpleDialog': 'tkinter.simpledialog',
+           'tkSimpleDialog': 'tkinter.simpledialog',
+           'tkColorChooser': 'tkinter.colorchooser',
+           'tkCommonDialog': 'tkinter.commondialog',
+           'Dialog': 'tkinter.dialog',
+           'Tkdnd': 'tkinter.dnd',
+           'tkFont': 'tkinter.font',
+           'tkMessageBox': 'tkinter.messagebox',
+           'ScrolledText': 'tkinter.scrolledtext',
+           'Tkconstants': 'tkinter.constants',
+           'Tix': 'tkinter.tix',
+           'ttk': 'tkinter.ttk',
+           'Tkinter': 'tkinter',
+           'markupbase': '_markupbase',
+           '_winreg': 'winreg',
+           'thread': '_thread',
+           'dummy_thread': '_dummy_thread',
+           # anydbm and whichdb are handled by fix_imports2
+           'dbhash': 'dbm.bsd',
+           'dumbdbm': 'dbm.dumb',
+           'dbm': 'dbm.ndbm',
+           'gdbm': 'dbm.gnu',
+           'xmlrpclib': 'xmlrpc.client',
+           'DocXMLRPCServer': 'xmlrpc.server',
+           'SimpleXMLRPCServer': 'xmlrpc.server',
+           'httplib': 'http.client',
+           'htmlentitydefs' : 'html.entities',
+           'HTMLParser' : 'html.parser',
+           'Cookie': 'http.cookies',
+           'cookielib': 'http.cookiejar',
+           'BaseHTTPServer': 'http.server',
+           'SimpleHTTPServer': 'http.server',
+           'CGIHTTPServer': 'http.server',
+           #'test.test_support': 'test.support',
+           'commands': 'subprocess',
+           'UserString' : 'collections',
+           'UserList' : 'collections',
+           'urlparse' : 'urllib.parse',
+           'robotparser' : 'urllib.robotparser',
+}
+
+
+def alternates(members):
+    return "(" + "|".join(map(repr, members)) + ")"
+
+
+def build_pattern(mapping=MAPPING):
+    mod_list = ' | '.join(["module_name='%s'" % key for key in mapping])
+    bare_names = alternates(mapping.keys())
+
+    yield """name_import=import_name< 'import' ((%s) |
+               multiple_imports=dotted_as_names< any* (%s) any* >) >
+          """ % (mod_list, mod_list)
+    yield """import_from< 'from' (%s) 'import' ['(']
+              ( any | import_as_name< any 'as' any > |
+                import_as_names< any* >)  [')'] >
+          """ % mod_list
+    yield """import_name< 'import' (dotted_as_name< (%s) 'as' any > |
+               multiple_imports=dotted_as_names<
+                 any* dotted_as_name< (%s) 'as' any > any* >) >
+          """ % (mod_list, mod_list)
+
+    # Find usages of module members in code e.g. thread.foo(bar)
+    yield "power< bare_with_attr=(%s) trailer<'.' any > any* >" % bare_names
+
+
+class FixImports(fixer_base.BaseFix):
+
+    BM_compatible = True
+    keep_line_order = True
+    # This is overridden in fix_imports2.
+    mapping = MAPPING
+
+    # We want to run this fixer late, so fix_import doesn't try to make stdlib
+    # renames into relative imports.
+    run_order = 6
+
+    def build_pattern(self):
+        return "|".join(build_pattern(self.mapping))
+
+    def compile_pattern(self):
+        # We override this, so MAPPING can be pragmatically altered and the
+        # changes will be reflected in PATTERN.
+        self.PATTERN = self.build_pattern()
+        super(FixImports, self).compile_pattern()
+
+    # Don't match the node if it's within another match.
+    def match(self, node):
+        match = super(FixImports, self).match
+        results = match(node)
+        if results:
+            # Module usage could be in the trailer of an attribute lookup, so we
+            # might have nested matches when "bare_with_attr" is present.
+            if "bare_with_attr" not in results and \
+                    any(match(obj) for obj in attr_chain(node, "parent")):
+                return False
+            return results
+        return False
+
+    def start_tree(self, tree, filename):
+        super(FixImports, self).start_tree(tree, filename)
+        self.replace = {}
+
+    def transform(self, node, results):
+        import_mod = results.get("module_name")
+        if import_mod:
+            mod_name = import_mod.value
+            new_name = self.mapping[mod_name]
+            import_mod.replace(Name(new_name, prefix=import_mod.prefix))
+            if "name_import" in results:
+                # If it's not a "from x import x, y" or "import x as y" import,
+                # marked its usage to be replaced.
+                self.replace[mod_name] = new_name
+            if "multiple_imports" in results:
+                # This is a nasty hack to fix multiple imports on a line (e.g.,
+                # "import StringIO, urlparse"). The problem is that I can't
+                # figure out an easy way to make a pattern recognize the keys of
+                # MAPPING randomly sprinkled in an import statement.
+                results = self.match(node)
+                if results:
+                    self.transform(node, results)
+        else:
+            # Replace usage of the module.
+            bare_name = results["bare_with_attr"][0]
+            new_name = self.replace.get(bare_name.value)
+            if new_name:
+                bare_name.replace(Name(new_name, prefix=bare_name.prefix))

Lib/lib2to3/fixes/fix_imports2.py

@@ -0,0 +1,16 @@
+"""Fix incompatible imports and module references that must be fixed after
+fix_imports."""
+from . import fix_imports
+
+
+MAPPING = {
+            'whichdb': 'dbm',
+            'anydbm': 'dbm',
+          }
+
+
+class FixImports2(fix_imports.FixImports):
+
+    run_order = 7
+
+    mapping = MAPPING

Lib/lib2to3/fixes/fix_input.py

@@ -0,0 +1,26 @@
+"""Fixer that changes input(...) into eval(input(...))."""
+# Author: Andre Roberge
+
+# Local imports
+from .. import fixer_base
+from ..fixer_util import Call, Name
+from .. import patcomp
+
+
+context = patcomp.compile_pattern("power< 'eval' trailer< '(' any ')' > >")
+
+
+class FixInput(fixer_base.BaseFix):
+    BM_compatible = True
+    PATTERN = """
+              power< 'input' args=trailer< '(' [any] ')' > >
+              """
+
+    def transform(self, node, results):
+        # If we're already wrapped in an eval() call, we're done.
+        if context.match(node.parent.parent):
+            return
+
+        new = node.clone()
+        new.prefix = ""
+        return Call(Name("eval"), [new], prefix=node.prefix)

Lib/lib2to3/fixes/fix_intern.py

@@ -0,0 +1,41 @@
+# Copyright 2006 Georg Brandl.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Fixer for intern().
+
+intern(s) -> sys.intern(s)"""
+
+# Local imports
+from .. import fixer_base
+from ..fixer_util import ImportAndCall, touch_import
+
+
+class FixIntern(fixer_base.BaseFix):
+    BM_compatible = True
+    order = "pre"
+
+    PATTERN = """
+    power< 'intern'
+           trailer< lpar='('
+                    ( not(arglist | argument<any '=' any>) obj=any
+                      | obj=arglist<(not argument<any '=' any>) any ','> )
+                    rpar=')' >
+           after=any*
+    >
+    """
+
+    def transform(self, node, results):
+        if results:
+            # I feel like we should be able to express this logic in the
+            # PATTERN above but I don't know how to do it so...
+            obj = results['obj']
+            if obj:
+                if obj.type == self.syms.star_expr:
+                    return  # Make no change.
+                if (obj.type == self.syms.argument and
+                    obj.children[0].value == '**'):
+                    return  # Make no change.
+        names = ('sys', 'intern')
+        new = ImportAndCall(node, results, names)
+        touch_import(None, 'sys', node)
+        return new

Lib/lib2to3/fixes/fix_isinstance.py

@@ -0,0 +1,52 @@
+# Copyright 2008 Armin Ronacher.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Fixer that cleans up a tuple argument to isinstance after the tokens
+in it were fixed.  This is mainly used to remove double occurrences of
+tokens as a leftover of the long -> int / unicode -> str conversion.
+
+eg.  isinstance(x, (int, long)) -> isinstance(x, (int, int))
+       -> isinstance(x, int)
+"""
+
+from .. import fixer_base
+from ..fixer_util import token
+
+
+class FixIsinstance(fixer_base.BaseFix):
+    BM_compatible = True
+    PATTERN = """
+    power<
+        'isinstance'
+        trailer< '(' arglist< any ',' atom< '('
+            args=testlist_gexp< any+ >
+        ')' > > ')' >
+    >
+    """
+
+    run_order = 6
+
+    def transform(self, node, results):
+        names_inserted = set()
+        testlist = results["args"]
+        args = testlist.children
+        new_args = []
+        iterator = enumerate(args)
+        for idx, arg in iterator:
+            if arg.type == token.NAME and arg.value in names_inserted:
+                if idx < len(args) - 1 and args[idx + 1].type == token.COMMA:
+                    next(iterator)
+                    continue
+            else:
+                new_args.append(arg)
+                if arg.type == token.NAME:
+                    names_inserted.add(arg.value)
+        if new_args and new_args[-1].type == token.COMMA:
+            del new_args[-1]
+        if len(new_args) == 1:
+            atom = testlist.parent
+            new_args[0].prefix = atom.prefix
+            atom.replace(new_args[0])
+        else:
+            args[:] = new_args
+            node.changed()

Lib/lib2to3/fixes/fix_itertools.py

@@ -0,0 +1,43 @@
+""" Fixer for itertools.(imap|ifilter|izip) --> (map|filter|zip) and
+    itertools.ifilterfalse --> itertools.filterfalse (bugs 2360-2363)
+
+    imports from itertools are fixed in fix_itertools_import.py
+
+    If itertools is imported as something else (ie: import itertools as it;
+    it.izip(spam, eggs)) method calls will not get fixed.
+    """
+
+# Local imports
+from .. import fixer_base
+from ..fixer_util import Name
+
+class FixItertools(fixer_base.BaseFix):
+    BM_compatible = True
+    it_funcs = "('imap'|'ifilter'|'izip'|'izip_longest'|'ifilterfalse')"
+    PATTERN = """
+              power< it='itertools'
+                  trailer<
+                     dot='.' func=%(it_funcs)s > trailer< '(' [any] ')' > >
+              |
+              power< func=%(it_funcs)s trailer< '(' [any] ')' > >
+              """ %(locals())
+
+    # Needs to be run after fix_(map|zip|filter)
+    run_order = 6
+
+    def transform(self, node, results):
+        prefix = None
+        func = results['func'][0]
+        if ('it' in results and
+            func.value not in ('ifilterfalse', 'izip_longest')):
+            dot, it = (results['dot'], results['it'])
+            # Remove the 'itertools'
+            prefix = it.prefix
+            it.remove()
+            # Replace the node which contains ('.', 'function') with the
+            # function (to be consistent with the second part of the pattern)
+            dot.remove()
+            func.parent.replace(func)
+
+        prefix = prefix or func.prefix
+        func.replace(Name(func.value[1:], prefix=prefix))

Lib/lib2to3/fixes/fix_itertools_imports.py

@@ -0,0 +1,57 @@
+""" Fixer for imports of itertools.(imap|ifilter|izip|ifilterfalse) """
+
+# Local imports
+from lib2to3 import fixer_base
+from lib2to3.fixer_util import BlankLine, syms, token
+
+
+class FixItertoolsImports(fixer_base.BaseFix):
+    BM_compatible = True
+    PATTERN = """
+              import_from< 'from' 'itertools' 'import' imports=any >
+              """ %(locals())
+
+    def transform(self, node, results):
+        imports = results['imports']
+        if imports.type == syms.import_as_name or not imports.children:
+            children = [imports]
+        else:
+            children = imports.children
+        for child in children[::2]:
+            if child.type == token.NAME:
+                member = child.value
+                name_node = child
+            elif child.type == token.STAR:
+                # Just leave the import as is.
+                return
+            else:
+                assert child.type == syms.import_as_name
+                name_node = child.children[0]
+            member_name = name_node.value
+            if member_name in ('imap', 'izip', 'ifilter'):
+                child.value = None
+                child.remove()
+            elif member_name in ('ifilterfalse', 'izip_longest'):
+                node.changed()
+                name_node.value = ('filterfalse' if member_name[1] == 'f'
+                                   else 'zip_longest')
+
+        # Make sure the import statement is still sane
+        children = imports.children[:] or [imports]
+        remove_comma = True
+        for child in children:
+            if remove_comma and child.type == token.COMMA:
+                child.remove()
+            else:
+                remove_comma ^= True
+
+        while children and children[-1].type == token.COMMA:
+            children.pop().remove()
+
+        # If there are no imports left, just get rid of the entire statement
+        if (not (imports.children or getattr(imports, 'value', None)) or
+            imports.parent is None):
+            p = node.prefix
+            node = BlankLine()
+            node.prefix = p
+            return node

Lib/lib2to3/fixes/fix_long.py

@@ -0,0 +1,19 @@
+# Copyright 2006 Google, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Fixer that turns 'long' into 'int' everywhere.
+"""
+
+# Local imports
+from lib2to3 import fixer_base
+from lib2to3.fixer_util import is_probably_builtin
+
+
+class FixLong(fixer_base.BaseFix):
+    BM_compatible = True
+    PATTERN = "'long'"
+
+    def transform(self, node, results):
+        if is_probably_builtin(node):
+            node.value = "int"
+            node.changed()

Lib/lib2to3/fixes/fix_map.py

@@ -0,0 +1,110 @@
+# Copyright 2007 Google, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Fixer that changes map(F, ...) into list(map(F, ...)) unless there
+exists a 'from future_builtins import map' statement in the top-level
+namespace.
+
+As a special case, map(None, X) is changed into list(X).  (This is
+necessary because the semantics are changed in this case -- the new
+map(None, X) is equivalent to [(x,) for x in X].)
+
+We avoid the transformation (except for the special case mentioned
+above) if the map() call is directly contained in iter(<>), list(<>),
+tuple(<>), sorted(<>), ...join(<>), or for V in <>:.
+
+NOTE: This is still not correct if the original code was depending on
+map(F, X, Y, ...) to go on until the longest argument is exhausted,
+substituting None for missing values -- like zip(), it now stops as
+soon as the shortest argument is exhausted.
+"""
+
+# Local imports
+from ..pgen2 import token
+from .. import fixer_base
+from ..fixer_util import Name, ArgList, Call, ListComp, in_special_context
+from ..pygram import python_symbols as syms
+from ..pytree import Node
+
+
+class FixMap(fixer_base.ConditionalFix):
+    BM_compatible = True
+
+    PATTERN = """
+    map_none=power<
+        'map'
+        trailer< '(' arglist< 'None' ',' arg=any [','] > ')' >
+        [extra_trailers=trailer*]
+    >
+    |
+    map_lambda=power<
+        'map'
+        trailer<
+            '('
+            arglist<
+                lambdef< 'lambda'
+                         (fp=NAME | vfpdef< '(' fp=NAME ')'> ) ':' xp=any
+                >
+                ','
+                it=any
+            >
+            ')'
+        >
+        [extra_trailers=trailer*]
+    >
+    |
+    power<
+        'map' args=trailer< '(' [any] ')' >
+        [extra_trailers=trailer*]
+    >
+    """
+
+    skip_on = 'future_builtins.map'
+
+    def transform(self, node, results):
+        if self.should_skip(node):
+            return
+
+        trailers = []
+        if 'extra_trailers' in results:
+            for t in results['extra_trailers']:
+                trailers.append(t.clone())
+
+        if node.parent.type == syms.simple_stmt:
+            self.warning(node, "You should use a for loop here")
+            new = node.clone()
+            new.prefix = ""
+            new = Call(Name("list"), [new])
+        elif "map_lambda" in results:
+            new = ListComp(results["xp"].clone(),
+                           results["fp"].clone(),
+                           results["it"].clone())
+            new = Node(syms.power, [new] + trailers, prefix="")
+
+        else:
+            if "map_none" in results:
+                new = results["arg"].clone()
+                new.prefix = ""
+            else:
+                if "args" in results:
+                    args = results["args"]
+                    if args.type == syms.trailer and \
+                       args.children[1].type == syms.arglist and \
+                       args.children[1].children[0].type == token.NAME and \
+                       args.children[1].children[0].value == "None":
+                        self.warning(node, "cannot convert map(None, ...) "
+                                     "with multiple arguments because map() "
+                                     "now truncates to the shortest sequence")
+                        return
+
+                    new = Node(syms.power, [Name("map"), args.clone()])
+                    new.prefix = ""
+
+                if in_special_context(node):
+                    return None
+
+            new = Node(syms.power, [Name("list"), ArgList([new])] + trailers)
+            new.prefix = ""
+
+        new.prefix = node.prefix
+        return new

Lib/lib2to3/fixes/fix_metaclass.py

@@ -0,0 +1,228 @@
+"""Fixer for __metaclass__ = X -> (metaclass=X) methods.
+
+   The various forms of classef (inherits nothing, inherits once, inherints
+   many) don't parse the same in the CST so we look at ALL classes for
+   a __metaclass__ and if we find one normalize the inherits to all be
+   an arglist.
+
+   For one-liner classes ('class X: pass') there is no indent/dedent so
+   we normalize those into having a suite.
+
+   Moving the __metaclass__ into the classdef can also cause the class
+   body to be empty so there is some special casing for that as well.
+
+   This fixer also tries very hard to keep original indenting and spacing
+   in all those corner cases.
+
+"""
+# Author: Jack Diederich
+
+# Local imports
+from .. import fixer_base
+from ..pygram import token
+from ..fixer_util import syms, Node, Leaf
+
+
+def has_metaclass(parent):
+    """ we have to check the cls_node without changing it.
+        There are two possibilities:
+          1)  clsdef => suite => simple_stmt => expr_stmt => Leaf('__meta')
+          2)  clsdef => simple_stmt => expr_stmt => Leaf('__meta')
+    """
+    for node in parent.children:
+        if node.type == syms.suite:
+            return has_metaclass(node)
+        elif node.type == syms.simple_stmt and node.children:
+            expr_node = node.children[0]
+            if expr_node.type == syms.expr_stmt and expr_node.children:
+                left_side = expr_node.children[0]
+                if isinstance(left_side, Leaf) and \
+                        left_side.value == '__metaclass__':
+                    return True
+    return False
+
+
+def fixup_parse_tree(cls_node):
+    """ one-line classes don't get a suite in the parse tree so we add
+        one to normalize the tree
+    """
+    for node in cls_node.children:
+        if node.type == syms.suite:
+            # already in the preferred format, do nothing
+            return
+
+    # !%@#! oneliners have no suite node, we have to fake one up
+    for i, node in enumerate(cls_node.children):
+        if node.type == token.COLON:
+            break
+    else:
+        raise ValueError("No class suite and no ':'!")
+
+    # move everything into a suite node
+    suite = Node(syms.suite, [])
+    while cls_node.children[i+1:]:
+        move_node = cls_node.children[i+1]
+        suite.append_child(move_node.clone())
+        move_node.remove()
+    cls_node.append_child(suite)
+    node = suite
+
+
+def fixup_simple_stmt(parent, i, stmt_node):
+    """ if there is a semi-colon all the parts count as part of the same
+        simple_stmt.  We just want the __metaclass__ part so we move
+        everything after the semi-colon into its own simple_stmt node
+    """
+    for semi_ind, node in enumerate(stmt_node.children):
+        if node.type == token.SEMI: # *sigh*
+            break
+    else:
+        return
+
+    node.remove() # kill the semicolon
+    new_expr = Node(syms.expr_stmt, [])
+    new_stmt = Node(syms.simple_stmt, [new_expr])
+    while stmt_node.children[semi_ind:]:
+        move_node = stmt_node.children[semi_ind]
+        new_expr.append_child(move_node.clone())
+        move_node.remove()
+    parent.insert_child(i, new_stmt)
+    new_leaf1 = new_stmt.children[0].children[0]
+    old_leaf1 = stmt_node.children[0].children[0]
+    new_leaf1.prefix = old_leaf1.prefix
+
+
+def remove_trailing_newline(node):
+    if node.children and node.children[-1].type == token.NEWLINE:
+        node.children[-1].remove()
+
+
+def find_metas(cls_node):
+    # find the suite node (Mmm, sweet nodes)
+    for node in cls_node.children:
+        if node.type == syms.suite:
+            break
+    else:
+        raise ValueError("No class suite!")
+
+    # look for simple_stmt[ expr_stmt[ Leaf('__metaclass__') ] ]
+    for i, simple_node in list(enumerate(node.children)):
+        if simple_node.type == syms.simple_stmt and simple_node.children:
+            expr_node = simple_node.children[0]
+            if expr_node.type == syms.expr_stmt and expr_node.children:
+                # Check if the expr_node is a simple assignment.
+                left_node = expr_node.children[0]
+                if isinstance(left_node, Leaf) and \
+                        left_node.value == '__metaclass__':
+                    # We found an assignment to __metaclass__.
+                    fixup_simple_stmt(node, i, simple_node)
+                    remove_trailing_newline(simple_node)
+                    yield (node, i, simple_node)
+
+
+def fixup_indent(suite):
+    """ If an INDENT is followed by a thing with a prefix then nuke the prefix
+        Otherwise we get in trouble when removing __metaclass__ at suite start
+    """
+    kids = suite.children[::-1]
+    # find the first indent
+    while kids:
+        node = kids.pop()
+        if node.type == token.INDENT:
+            break
+
+    # find the first Leaf
+    while kids:
+        node = kids.pop()
+        if isinstance(node, Leaf) and node.type != token.DEDENT:
+            if node.prefix:
+                node.prefix = ''
+            return
+        else:
+            kids.extend(node.children[::-1])
+
+
+class FixMetaclass(fixer_base.BaseFix):
+    BM_compatible = True
+
+    PATTERN = """
+    classdef<any*>
+    """
+
+    def transform(self, node, results):
+        if not has_metaclass(node):
+            return
+
+        fixup_parse_tree(node)
+
+        # find metaclasses, keep the last one
+        last_metaclass = None
+        for suite, i, stmt in find_metas(node):
+            last_metaclass = stmt
+            stmt.remove()
+
+        text_type = node.children[0].type # always Leaf(nnn, 'class')
+
+        # figure out what kind of classdef we have
+        if len(node.children) == 7:
+            # Node(classdef, ['class', 'name', '(', arglist, ')', ':', suite])
+            #                 0        1       2    3        4    5    6
+            if node.children[3].type == syms.arglist:
+                arglist = node.children[3]
+            # Node(classdef, ['class', 'name', '(', 'Parent', ')', ':', suite])
+            else:
+                parent = node.children[3].clone()
+                arglist = Node(syms.arglist, [parent])
+                node.set_child(3, arglist)
+        elif len(node.children) == 6:
+            # Node(classdef, ['class', 'name', '(',  ')', ':', suite])
+            #                 0        1       2     3    4    5
+            arglist = Node(syms.arglist, [])
+            node.insert_child(3, arglist)
+        elif len(node.children) == 4:
+            # Node(classdef, ['class', 'name', ':', suite])
+            #                 0        1       2    3
+            arglist = Node(syms.arglist, [])
+            node.insert_child(2, Leaf(token.RPAR, ')'))
+            node.insert_child(2, arglist)
+            node.insert_child(2, Leaf(token.LPAR, '('))
+        else:
+            raise ValueError("Unexpected class definition")
+
+        # now stick the metaclass in the arglist
+        meta_txt = last_metaclass.children[0].children[0]
+        meta_txt.value = 'metaclass'
+        orig_meta_prefix = meta_txt.prefix
+
+        if arglist.children:
+            arglist.append_child(Leaf(token.COMMA, ','))
+            meta_txt.prefix = ' '
+        else:
+            meta_txt.prefix = ''
+
+        # compact the expression "metaclass = Meta" -> "metaclass=Meta"
+        expr_stmt = last_metaclass.children[0]
+        assert expr_stmt.type == syms.expr_stmt
+        expr_stmt.children[1].prefix = ''
+        expr_stmt.children[2].prefix = ''
+
+        arglist.append_child(last_metaclass)
+
+        fixup_indent(suite)
+
+        # check for empty suite
+        if not suite.children:
+            # one-liner that was just __metaclass_
+            suite.remove()
+            pass_leaf = Leaf(text_type, 'pass')
+            pass_leaf.prefix = orig_meta_prefix
+            node.append_child(pass_leaf)
+            node.append_child(Leaf(token.NEWLINE, '\n'))
+
+        elif len(suite.children) > 1 and \
+                 (suite.children[-2].type == token.INDENT and
+                  suite.children[-1].type == token.DEDENT):
+            # there was only one line in the class body and it was __metaclass__
+            pass_leaf = Leaf(text_type, 'pass')
+            suite.insert_child(-1, pass_leaf)
+            suite.insert_child(-1, Leaf(token.NEWLINE, '\n'))

Lib/lib2to3/fixes/fix_methodattrs.py

@@ -0,0 +1,24 @@
+"""Fix bound method attributes (method.im_? -> method.__?__).
+"""
+# Author: Christian Heimes
+
+# Local imports
+from .. import fixer_base
+from ..fixer_util import Name
+
+MAP = {
+    "im_func" : "__func__",
+    "im_self" : "__self__",
+    "im_class" : "__self__.__class__"
+    }
+
+class FixMethodattrs(fixer_base.BaseFix):
+    BM_compatible = True
+    PATTERN = """
+    power< any+ trailer< '.' attr=('im_func' | 'im_self' | 'im_class') > any* >
+    """
+
+    def transform(self, node, results):
+        attr = results["attr"][0]
+        new = MAP[attr.value]
+        attr.replace(Name(new, prefix=attr.prefix))