442 lines
16 KiB
Python
442 lines
16 KiB
Python
"""Implementation of JSONEncoder
|
|
"""
|
|
import re
|
|
|
|
try:
|
|
from _json import encode_basestring_ascii as c_encode_basestring_ascii
|
|
except ImportError:
|
|
c_encode_basestring_ascii = None
|
|
try:
|
|
from _json import encode_basestring as c_encode_basestring
|
|
except ImportError:
|
|
c_encode_basestring = None
|
|
try:
|
|
from _json import make_encoder as c_make_encoder
|
|
except ImportError:
|
|
c_make_encoder = None
|
|
|
|
ESCAPE = re.compile(r'[\x00-\x1f\\"\b\f\n\r\t]')
|
|
ESCAPE_ASCII = re.compile(r'([\\"]|[^\ -~])')
|
|
HAS_UTF8 = re.compile(b'[\x80-\xff]')
|
|
ESCAPE_DCT = {
|
|
'\\': '\\\\',
|
|
'"': '\\"',
|
|
'\b': '\\b',
|
|
'\f': '\\f',
|
|
'\n': '\\n',
|
|
'\r': '\\r',
|
|
'\t': '\\t',
|
|
}
|
|
for i in range(0x20):
|
|
ESCAPE_DCT.setdefault(chr(i), '\\u{0:04x}'.format(i))
|
|
#ESCAPE_DCT.setdefault(chr(i), '\\u%04x' % (i,))
|
|
|
|
INFINITY = float('inf')
|
|
|
|
def py_encode_basestring(s):
|
|
"""Return a JSON representation of a Python string
|
|
|
|
"""
|
|
def replace(match):
|
|
return ESCAPE_DCT[match.group(0)]
|
|
return '"' + ESCAPE.sub(replace, s) + '"'
|
|
|
|
|
|
encode_basestring = (c_encode_basestring or py_encode_basestring)
|
|
|
|
|
|
def py_encode_basestring_ascii(s):
|
|
"""Return an ASCII-only JSON representation of a Python string
|
|
|
|
"""
|
|
def replace(match):
|
|
s = match.group(0)
|
|
try:
|
|
return ESCAPE_DCT[s]
|
|
except KeyError:
|
|
n = ord(s)
|
|
if n < 0x10000:
|
|
return '\\u{0:04x}'.format(n)
|
|
#return '\\u%04x' % (n,)
|
|
else:
|
|
# surrogate pair
|
|
n -= 0x10000
|
|
s1 = 0xd800 | ((n >> 10) & 0x3ff)
|
|
s2 = 0xdc00 | (n & 0x3ff)
|
|
return '\\u{0:04x}\\u{1:04x}'.format(s1, s2)
|
|
return '"' + ESCAPE_ASCII.sub(replace, s) + '"'
|
|
|
|
|
|
encode_basestring_ascii = (
|
|
c_encode_basestring_ascii or py_encode_basestring_ascii)
|
|
|
|
class JSONEncoder(object):
|
|
"""Extensible JSON <http://json.org> encoder for Python data structures.
|
|
|
|
Supports the following objects and types by default:
|
|
|
|
+-------------------+---------------+
|
|
| Python | JSON |
|
|
+===================+===============+
|
|
| dict | object |
|
|
+-------------------+---------------+
|
|
| list, tuple | array |
|
|
+-------------------+---------------+
|
|
| str | string |
|
|
+-------------------+---------------+
|
|
| int, float | number |
|
|
+-------------------+---------------+
|
|
| True | true |
|
|
+-------------------+---------------+
|
|
| False | false |
|
|
+-------------------+---------------+
|
|
| None | null |
|
|
+-------------------+---------------+
|
|
|
|
To extend this to recognize other objects, subclass and implement a
|
|
``.default()`` method with another method that returns a serializable
|
|
object for ``o`` if possible, otherwise it should call the superclass
|
|
implementation (to raise ``TypeError``).
|
|
|
|
"""
|
|
item_separator = ', '
|
|
key_separator = ': '
|
|
def __init__(self, *, skipkeys=False, ensure_ascii=True,
|
|
check_circular=True, allow_nan=True, sort_keys=False,
|
|
indent=None, separators=None, default=None):
|
|
"""Constructor for JSONEncoder, with sensible defaults.
|
|
|
|
If skipkeys is false, then it is a TypeError to attempt
|
|
encoding of keys that are not str, int, float or None. If
|
|
skipkeys is True, such items are simply skipped.
|
|
|
|
If ensure_ascii is true, the output is guaranteed to be str
|
|
objects with all incoming non-ASCII characters escaped. If
|
|
ensure_ascii is false, the output can contain non-ASCII characters.
|
|
|
|
If check_circular is true, then lists, dicts, and custom encoded
|
|
objects will be checked for circular references during encoding to
|
|
prevent an infinite recursion (which would cause an OverflowError).
|
|
Otherwise, no such check takes place.
|
|
|
|
If allow_nan is true, then NaN, Infinity, and -Infinity will be
|
|
encoded as such. This behavior is not JSON specification compliant,
|
|
but is consistent with most JavaScript based encoders and decoders.
|
|
Otherwise, it will be a ValueError to encode such floats.
|
|
|
|
If sort_keys is true, then the output of dictionaries will be
|
|
sorted by key; this is useful for regression tests to ensure
|
|
that JSON serializations can be compared on a day-to-day basis.
|
|
|
|
If indent is a non-negative integer, then JSON array
|
|
elements and object members will be pretty-printed with that
|
|
indent level. An indent level of 0 will only insert newlines.
|
|
None is the most compact representation.
|
|
|
|
If specified, separators should be an (item_separator, key_separator)
|
|
tuple. The default is (', ', ': ') if *indent* is ``None`` and
|
|
(',', ': ') otherwise. To get the most compact JSON representation,
|
|
you should specify (',', ':') to eliminate whitespace.
|
|
|
|
If specified, default is a function that gets called for objects
|
|
that can't otherwise be serialized. It should return a JSON encodable
|
|
version of the object or raise a ``TypeError``.
|
|
|
|
"""
|
|
|
|
self.skipkeys = skipkeys
|
|
self.ensure_ascii = ensure_ascii
|
|
self.check_circular = check_circular
|
|
self.allow_nan = allow_nan
|
|
self.sort_keys = sort_keys
|
|
self.indent = indent
|
|
if separators is not None:
|
|
self.item_separator, self.key_separator = separators
|
|
elif indent is not None:
|
|
self.item_separator = ','
|
|
if default is not None:
|
|
self.default = default
|
|
|
|
def default(self, o):
|
|
"""Implement this method in a subclass such that it returns
|
|
a serializable object for ``o``, or calls the base implementation
|
|
(to raise a ``TypeError``).
|
|
|
|
For example, to support arbitrary iterators, you could
|
|
implement default like this::
|
|
|
|
def default(self, o):
|
|
try:
|
|
iterable = iter(o)
|
|
except TypeError:
|
|
pass
|
|
else:
|
|
return list(iterable)
|
|
# Let the base class default method raise the TypeError
|
|
return JSONEncoder.default(self, o)
|
|
|
|
"""
|
|
raise TypeError(f'Object of type {o.__class__.__name__} '
|
|
f'is not JSON serializable')
|
|
|
|
def encode(self, o):
|
|
"""Return a JSON string representation of a Python data structure.
|
|
|
|
>>> from json.encoder import JSONEncoder
|
|
>>> JSONEncoder().encode({"foo": ["bar", "baz"]})
|
|
'{"foo": ["bar", "baz"]}'
|
|
|
|
"""
|
|
# This is for extremely simple cases and benchmarks.
|
|
if isinstance(o, str):
|
|
if self.ensure_ascii:
|
|
return encode_basestring_ascii(o)
|
|
else:
|
|
return encode_basestring(o)
|
|
# This doesn't pass the iterator directly to ''.join() because the
|
|
# exceptions aren't as detailed. The list call should be roughly
|
|
# equivalent to the PySequence_Fast that ''.join() would do.
|
|
chunks = self.iterencode(o, _one_shot=True)
|
|
if not isinstance(chunks, (list, tuple)):
|
|
chunks = list(chunks)
|
|
return ''.join(chunks)
|
|
|
|
def iterencode(self, o, _one_shot=False):
|
|
"""Encode the given object and yield each string
|
|
representation as available.
|
|
|
|
For example::
|
|
|
|
for chunk in JSONEncoder().iterencode(bigobject):
|
|
mysocket.write(chunk)
|
|
|
|
"""
|
|
if self.check_circular:
|
|
markers = {}
|
|
else:
|
|
markers = None
|
|
if self.ensure_ascii:
|
|
_encoder = encode_basestring_ascii
|
|
else:
|
|
_encoder = encode_basestring
|
|
|
|
def floatstr(o, allow_nan=self.allow_nan,
|
|
_repr=float.__repr__, _inf=INFINITY, _neginf=-INFINITY):
|
|
# Check for specials. Note that this type of test is processor
|
|
# and/or platform-specific, so do tests which don't depend on the
|
|
# internals.
|
|
|
|
if o != o:
|
|
text = 'NaN'
|
|
elif o == _inf:
|
|
text = 'Infinity'
|
|
elif o == _neginf:
|
|
text = '-Infinity'
|
|
else:
|
|
return _repr(o)
|
|
|
|
if not allow_nan:
|
|
raise ValueError(
|
|
"Out of range float values are not JSON compliant: " +
|
|
repr(o))
|
|
|
|
return text
|
|
|
|
|
|
if (_one_shot and c_make_encoder is not None
|
|
and self.indent is None):
|
|
_iterencode = c_make_encoder(
|
|
markers, self.default, _encoder, self.indent,
|
|
self.key_separator, self.item_separator, self.sort_keys,
|
|
self.skipkeys, self.allow_nan)
|
|
else:
|
|
_iterencode = _make_iterencode(
|
|
markers, self.default, _encoder, self.indent, floatstr,
|
|
self.key_separator, self.item_separator, self.sort_keys,
|
|
self.skipkeys, _one_shot)
|
|
return _iterencode(o, 0)
|
|
|
|
def _make_iterencode(markers, _default, _encoder, _indent, _floatstr,
|
|
_key_separator, _item_separator, _sort_keys, _skipkeys, _one_shot,
|
|
## HACK: hand-optimized bytecode; turn globals into locals
|
|
ValueError=ValueError,
|
|
dict=dict,
|
|
float=float,
|
|
id=id,
|
|
int=int,
|
|
isinstance=isinstance,
|
|
list=list,
|
|
str=str,
|
|
tuple=tuple,
|
|
_intstr=int.__str__,
|
|
):
|
|
|
|
if _indent is not None and not isinstance(_indent, str):
|
|
_indent = ' ' * _indent
|
|
|
|
def _iterencode_list(lst, _current_indent_level):
|
|
if not lst:
|
|
yield '[]'
|
|
return
|
|
if markers is not None:
|
|
markerid = id(lst)
|
|
if markerid in markers:
|
|
raise ValueError("Circular reference detected")
|
|
markers[markerid] = lst
|
|
buf = '['
|
|
if _indent is not None:
|
|
_current_indent_level += 1
|
|
newline_indent = '\n' + _indent * _current_indent_level
|
|
separator = _item_separator + newline_indent
|
|
buf += newline_indent
|
|
else:
|
|
newline_indent = None
|
|
separator = _item_separator
|
|
first = True
|
|
for value in lst:
|
|
if first:
|
|
first = False
|
|
else:
|
|
buf = separator
|
|
if isinstance(value, str):
|
|
yield buf + _encoder(value)
|
|
elif value is None:
|
|
yield buf + 'null'
|
|
elif value is True:
|
|
yield buf + 'true'
|
|
elif value is False:
|
|
yield buf + 'false'
|
|
elif isinstance(value, int):
|
|
# Subclasses of int/float may override __str__, but we still
|
|
# want to encode them as integers/floats in JSON. One example
|
|
# within the standard library is IntEnum.
|
|
yield buf + _intstr(value)
|
|
elif isinstance(value, float):
|
|
# see comment above for int
|
|
yield buf + _floatstr(value)
|
|
else:
|
|
yield buf
|
|
if isinstance(value, (list, tuple)):
|
|
chunks = _iterencode_list(value, _current_indent_level)
|
|
elif isinstance(value, dict):
|
|
chunks = _iterencode_dict(value, _current_indent_level)
|
|
else:
|
|
chunks = _iterencode(value, _current_indent_level)
|
|
yield from chunks
|
|
if newline_indent is not None:
|
|
_current_indent_level -= 1
|
|
yield '\n' + _indent * _current_indent_level
|
|
yield ']'
|
|
if markers is not None:
|
|
del markers[markerid]
|
|
|
|
def _iterencode_dict(dct, _current_indent_level):
|
|
if not dct:
|
|
yield '{}'
|
|
return
|
|
if markers is not None:
|
|
markerid = id(dct)
|
|
if markerid in markers:
|
|
raise ValueError("Circular reference detected")
|
|
markers[markerid] = dct
|
|
yield '{'
|
|
if _indent is not None:
|
|
_current_indent_level += 1
|
|
newline_indent = '\n' + _indent * _current_indent_level
|
|
item_separator = _item_separator + newline_indent
|
|
yield newline_indent
|
|
else:
|
|
newline_indent = None
|
|
item_separator = _item_separator
|
|
first = True
|
|
if _sort_keys:
|
|
items = sorted(dct.items(), key=lambda kv: kv[0])
|
|
else:
|
|
items = dct.items()
|
|
for key, value in items:
|
|
if isinstance(key, str):
|
|
pass
|
|
# JavaScript is weakly typed for these, so it makes sense to
|
|
# also allow them. Many encoders seem to do something like this.
|
|
elif isinstance(key, float):
|
|
# see comment for int/float in _make_iterencode
|
|
key = _floatstr(key)
|
|
elif key is True:
|
|
key = 'true'
|
|
elif key is False:
|
|
key = 'false'
|
|
elif key is None:
|
|
key = 'null'
|
|
elif isinstance(key, int):
|
|
# see comment for int/float in _make_iterencode
|
|
key = _intstr(key)
|
|
elif _skipkeys:
|
|
continue
|
|
else:
|
|
raise TypeError(f'keys must be str, int, float, bool or None, '
|
|
f'not {key.__class__.__name__}')
|
|
if first:
|
|
first = False
|
|
else:
|
|
yield item_separator
|
|
yield _encoder(key)
|
|
yield _key_separator
|
|
if isinstance(value, str):
|
|
yield _encoder(value)
|
|
elif value is None:
|
|
yield 'null'
|
|
elif value is True:
|
|
yield 'true'
|
|
elif value is False:
|
|
yield 'false'
|
|
elif isinstance(value, int):
|
|
# see comment for int/float in _make_iterencode
|
|
yield _intstr(value)
|
|
elif isinstance(value, float):
|
|
# see comment for int/float in _make_iterencode
|
|
yield _floatstr(value)
|
|
else:
|
|
if isinstance(value, (list, tuple)):
|
|
chunks = _iterencode_list(value, _current_indent_level)
|
|
elif isinstance(value, dict):
|
|
chunks = _iterencode_dict(value, _current_indent_level)
|
|
else:
|
|
chunks = _iterencode(value, _current_indent_level)
|
|
yield from chunks
|
|
if newline_indent is not None:
|
|
_current_indent_level -= 1
|
|
yield '\n' + _indent * _current_indent_level
|
|
yield '}'
|
|
if markers is not None:
|
|
del markers[markerid]
|
|
|
|
def _iterencode(o, _current_indent_level):
|
|
if isinstance(o, str):
|
|
yield _encoder(o)
|
|
elif o is None:
|
|
yield 'null'
|
|
elif o is True:
|
|
yield 'true'
|
|
elif o is False:
|
|
yield 'false'
|
|
elif isinstance(o, int):
|
|
# see comment for int/float in _make_iterencode
|
|
yield _intstr(o)
|
|
elif isinstance(o, float):
|
|
# see comment for int/float in _make_iterencode
|
|
yield _floatstr(o)
|
|
elif isinstance(o, (list, tuple)):
|
|
yield from _iterencode_list(o, _current_indent_level)
|
|
elif isinstance(o, dict):
|
|
yield from _iterencode_dict(o, _current_indent_level)
|
|
else:
|
|
if markers is not None:
|
|
markerid = id(o)
|
|
if markerid in markers:
|
|
raise ValueError("Circular reference detected")
|
|
markers[markerid] = o
|
|
o = _default(o)
|
|
yield from _iterencode(o, _current_indent_level)
|
|
if markers is not None:
|
|
del markers[markerid]
|
|
return _iterencode
|