402 lines
15 KiB
Python
402 lines
15 KiB
Python
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"""Parse a Python module and describe its classes and functions.
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Parse enough of a Python file to recognize imports and class and
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function definitions, and to find out the superclasses of a class.
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The interface consists of a single function:
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readmodule_ex(module, path=None)
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where module is the name of a Python module, and path is an optional
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list of directories where the module is to be searched. If present,
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path is prepended to the system search path sys.path. The return value
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is a dictionary. The keys of the dictionary are the names of the
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classes and functions defined in the module (including classes that are
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defined via the from XXX import YYY construct). The values are
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instances of classes Class and Function. One special key/value pair is
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present for packages: the key '__path__' has a list as its value which
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contains the package search path.
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Classes and Functions have a common superclass: _Object. Every instance
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has the following attributes:
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module -- name of the module;
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name -- name of the object;
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file -- file in which the object is defined;
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lineno -- line in the file where the object's definition starts;
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parent -- parent of this object, if any;
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children -- nested objects contained in this object.
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The 'children' attribute is a dictionary mapping names to objects.
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Instances of Function describe functions with the attributes from _Object.
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Instances of Class describe classes with the attributes from _Object,
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plus the following:
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super -- list of super classes (Class instances if possible);
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methods -- mapping of method names to beginning line numbers.
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If the name of a super class is not recognized, the corresponding
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entry in the list of super classes is not a class instance but a
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string giving the name of the super class. Since import statements
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are recognized and imported modules are scanned as well, this
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shouldn't happen often.
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"""
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import io
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import sys
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import importlib.util
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import tokenize
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from token import NAME, DEDENT, OP
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__all__ = ["readmodule", "readmodule_ex", "Class", "Function"]
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_modules = {} # Initialize cache of modules we've seen.
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class _Object:
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"Informaton about Python class or function."
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def __init__(self, module, name, file, lineno, parent):
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self.module = module
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self.name = name
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self.file = file
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self.lineno = lineno
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self.parent = parent
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self.children = {}
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def _addchild(self, name, obj):
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self.children[name] = obj
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class Function(_Object):
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"Information about a Python function, including methods."
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def __init__(self, module, name, file, lineno, parent=None):
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_Object.__init__(self, module, name, file, lineno, parent)
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class Class(_Object):
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"Information about a Python class."
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def __init__(self, module, name, super, file, lineno, parent=None):
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_Object.__init__(self, module, name, file, lineno, parent)
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self.super = [] if super is None else super
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self.methods = {}
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def _addmethod(self, name, lineno):
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self.methods[name] = lineno
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def _nest_function(ob, func_name, lineno):
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"Return a Function after nesting within ob."
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newfunc = Function(ob.module, func_name, ob.file, lineno, ob)
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ob._addchild(func_name, newfunc)
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if isinstance(ob, Class):
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ob._addmethod(func_name, lineno)
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return newfunc
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def _nest_class(ob, class_name, lineno, super=None):
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"Return a Class after nesting within ob."
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newclass = Class(ob.module, class_name, super, ob.file, lineno, ob)
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ob._addchild(class_name, newclass)
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return newclass
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def readmodule(module, path=None):
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"""Return Class objects for the top-level classes in module.
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This is the original interface, before Functions were added.
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"""
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res = {}
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for key, value in _readmodule(module, path or []).items():
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if isinstance(value, Class):
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res[key] = value
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return res
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def readmodule_ex(module, path=None):
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"""Return a dictionary with all functions and classes in module.
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Search for module in PATH + sys.path.
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If possible, include imported superclasses.
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Do this by reading source, without importing (and executing) it.
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"""
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return _readmodule(module, path or [])
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def _readmodule(module, path, inpackage=None):
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"""Do the hard work for readmodule[_ex].
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If inpackage is given, it must be the dotted name of the package in
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which we are searching for a submodule, and then PATH must be the
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package search path; otherwise, we are searching for a top-level
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module, and path is combined with sys.path.
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"""
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# Compute the full module name (prepending inpackage if set).
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if inpackage is not None:
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fullmodule = "%s.%s" % (inpackage, module)
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else:
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fullmodule = module
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# Check in the cache.
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if fullmodule in _modules:
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return _modules[fullmodule]
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# Initialize the dict for this module's contents.
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tree = {}
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# Check if it is a built-in module; we don't do much for these.
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if module in sys.builtin_module_names and inpackage is None:
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_modules[module] = tree
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return tree
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# Check for a dotted module name.
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i = module.rfind('.')
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if i >= 0:
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package = module[:i]
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submodule = module[i+1:]
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parent = _readmodule(package, path, inpackage)
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if inpackage is not None:
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package = "%s.%s" % (inpackage, package)
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if not '__path__' in parent:
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raise ImportError('No package named {}'.format(package))
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return _readmodule(submodule, parent['__path__'], package)
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# Search the path for the module.
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f = None
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if inpackage is not None:
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search_path = path
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else:
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search_path = path + sys.path
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spec = importlib.util._find_spec_from_path(fullmodule, search_path)
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_modules[fullmodule] = tree
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# Is module a package?
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if spec.submodule_search_locations is not None:
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tree['__path__'] = spec.submodule_search_locations
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try:
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source = spec.loader.get_source(fullmodule)
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if source is None:
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return tree
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except (AttributeError, ImportError):
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# If module is not Python source, we cannot do anything.
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return tree
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fname = spec.loader.get_filename(fullmodule)
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return _create_tree(fullmodule, path, fname, source, tree, inpackage)
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def _create_tree(fullmodule, path, fname, source, tree, inpackage):
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"""Return the tree for a particular module.
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fullmodule (full module name), inpackage+module, becomes o.module.
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path is passed to recursive calls of _readmodule.
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fname becomes o.file.
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source is tokenized. Imports cause recursive calls to _readmodule.
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tree is {} or {'__path__': <submodule search locations>}.
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inpackage, None or string, is passed to recursive calls of _readmodule.
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The effect of recursive calls is mutation of global _modules.
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"""
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f = io.StringIO(source)
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stack = [] # Initialize stack of (class, indent) pairs.
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g = tokenize.generate_tokens(f.readline)
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try:
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for tokentype, token, start, _end, _line in g:
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if tokentype == DEDENT:
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lineno, thisindent = start
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# Close previous nested classes and defs.
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while stack and stack[-1][1] >= thisindent:
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del stack[-1]
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elif token == 'def':
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lineno, thisindent = start
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# Close previous nested classes and defs.
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while stack and stack[-1][1] >= thisindent:
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del stack[-1]
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tokentype, func_name, start = next(g)[0:3]
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if tokentype != NAME:
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continue # Skip def with syntax error.
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cur_func = None
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if stack:
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cur_obj = stack[-1][0]
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cur_func = _nest_function(cur_obj, func_name, lineno)
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else:
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# It is just a function.
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cur_func = Function(fullmodule, func_name, fname, lineno)
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tree[func_name] = cur_func
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stack.append((cur_func, thisindent))
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elif token == 'class':
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lineno, thisindent = start
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# Close previous nested classes and defs.
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while stack and stack[-1][1] >= thisindent:
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del stack[-1]
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tokentype, class_name, start = next(g)[0:3]
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if tokentype != NAME:
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continue # Skip class with syntax error.
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# Parse what follows the class name.
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tokentype, token, start = next(g)[0:3]
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inherit = None
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if token == '(':
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names = [] # Initialize list of superclasses.
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level = 1
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super = [] # Tokens making up current superclass.
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while True:
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tokentype, token, start = next(g)[0:3]
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if token in (')', ',') and level == 1:
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n = "".join(super)
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if n in tree:
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# We know this super class.
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n = tree[n]
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else:
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c = n.split('.')
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if len(c) > 1:
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# Super class form is module.class:
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# look in module for class.
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m = c[-2]
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c = c[-1]
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if m in _modules:
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d = _modules[m]
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if c in d:
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n = d[c]
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names.append(n)
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super = []
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if token == '(':
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level += 1
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elif token == ')':
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level -= 1
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if level == 0:
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break
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elif token == ',' and level == 1:
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pass
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# Only use NAME and OP (== dot) tokens for type name.
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elif tokentype in (NAME, OP) and level == 1:
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super.append(token)
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# Expressions in the base list are not supported.
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inherit = names
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if stack:
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cur_obj = stack[-1][0]
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cur_class = _nest_class(
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cur_obj, class_name, lineno, inherit)
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else:
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cur_class = Class(fullmodule, class_name, inherit,
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fname, lineno)
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tree[class_name] = cur_class
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stack.append((cur_class, thisindent))
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elif token == 'import' and start[1] == 0:
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modules = _getnamelist(g)
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for mod, _mod2 in modules:
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try:
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# Recursively read the imported module.
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if inpackage is None:
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_readmodule(mod, path)
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else:
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try:
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_readmodule(mod, path, inpackage)
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except ImportError:
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_readmodule(mod, [])
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except:
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# If we can't find or parse the imported module,
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# too bad -- don't die here.
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pass
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elif token == 'from' and start[1] == 0:
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mod, token = _getname(g)
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if not mod or token != "import":
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continue
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names = _getnamelist(g)
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try:
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# Recursively read the imported module.
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d = _readmodule(mod, path, inpackage)
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except:
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# If we can't find or parse the imported module,
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# too bad -- don't die here.
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continue
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# Add any classes that were defined in the imported module
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# to our name space if they were mentioned in the list.
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for n, n2 in names:
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if n in d:
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tree[n2 or n] = d[n]
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elif n == '*':
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# Don't add names that start with _.
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for n in d:
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if n[0] != '_':
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tree[n] = d[n]
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except StopIteration:
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pass
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f.close()
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return tree
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def _getnamelist(g):
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"""Return list of (dotted-name, as-name or None) tuples for token source g.
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An as-name is the name that follows 'as' in an as clause.
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"""
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names = []
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while True:
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name, token = _getname(g)
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if not name:
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break
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if token == 'as':
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name2, token = _getname(g)
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else:
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name2 = None
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names.append((name, name2))
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while token != "," and "\n" not in token:
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token = next(g)[1]
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if token != ",":
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break
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return names
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def _getname(g):
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"Return (dotted-name or None, next-token) tuple for token source g."
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parts = []
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tokentype, token = next(g)[0:2]
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if tokentype != NAME and token != '*':
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return (None, token)
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parts.append(token)
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while True:
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tokentype, token = next(g)[0:2]
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if token != '.':
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break
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tokentype, token = next(g)[0:2]
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if tokentype != NAME:
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break
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parts.append(token)
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return (".".join(parts), token)
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def _main():
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"Print module output (default this file) for quick visual check."
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import os
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try:
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mod = sys.argv[1]
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except:
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mod = __file__
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if os.path.exists(mod):
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path = [os.path.dirname(mod)]
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mod = os.path.basename(mod)
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if mod.lower().endswith(".py"):
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mod = mod[:-3]
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else:
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path = []
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tree = readmodule_ex(mod, path)
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lineno_key = lambda a: getattr(a, 'lineno', 0)
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objs = sorted(tree.values(), key=lineno_key, reverse=True)
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indent_level = 2
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while objs:
|
||
|
|
obj = objs.pop()
|
||
|
|
if isinstance(obj, list):
|
||
|
|
# Value is a __path__ key.
|
||
|
|
continue
|
||
|
|
if not hasattr(obj, 'indent'):
|
||
|
|
obj.indent = 0
|
||
|
|
|
||
|
|
if isinstance(obj, _Object):
|
||
|
|
new_objs = sorted(obj.children.values(),
|
||
|
|
key=lineno_key, reverse=True)
|
||
|
|
for ob in new_objs:
|
||
|
|
ob.indent = obj.indent + indent_level
|
||
|
|
objs.extend(new_objs)
|
||
|
|
if isinstance(obj, Class):
|
||
|
|
print("{}class {} {} {}"
|
||
|
|
.format(' ' * obj.indent, obj.name, obj.super, obj.lineno))
|
||
|
|
elif isinstance(obj, Function):
|
||
|
|
print("{}def {} {}".format(' ' * obj.indent, obj.name, obj.lineno))
|
||
|
|
|
||
|
|
if __name__ == "__main__":
|
||
|
|
_main()
|