602 lines
23 KiB
Python
602 lines
23 KiB
Python
"""Implementation of JSONEncoder
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"""
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from __future__ import absolute_import
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import re
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from operator import itemgetter
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from decimal import Decimal
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from .compat import u, unichr, binary_type, string_types, integer_types, PY3
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def _import_speedups():
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try:
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from . import _speedups
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return _speedups.encode_basestring_ascii, _speedups.make_encoder
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except ImportError:
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return None, None
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c_encode_basestring_ascii, c_make_encoder = _import_speedups()
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from .decoder import PosInf
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#ESCAPE = re.compile(ur'[\x00-\x1f\\"\b\f\n\r\t\u2028\u2029]')
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# This is required because u() will mangle the string and ur'' isn't valid
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# python3 syntax
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ESCAPE = re.compile(u'[\\x00-\\x1f\\\\"\\b\\f\\n\\r\\t\u2028\u2029]')
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ESCAPE_ASCII = re.compile(r'([\\"]|[^\ -~])')
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HAS_UTF8 = re.compile(r'[\x80-\xff]')
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ESCAPE_DCT = {
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'\\': '\\\\',
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'"': '\\"',
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'\b': '\\b',
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'\f': '\\f',
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'\n': '\\n',
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'\r': '\\r',
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'\t': '\\t',
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}
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for i in range(0x20):
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#ESCAPE_DCT.setdefault(chr(i), '\\u{0:04x}'.format(i))
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ESCAPE_DCT.setdefault(chr(i), '\\u%04x' % (i,))
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for i in [0x2028, 0x2029]:
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ESCAPE_DCT.setdefault(unichr(i), '\\u%04x' % (i,))
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FLOAT_REPR = repr
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def encode_basestring(s, _PY3=PY3, _q=u('"')):
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"""Return a JSON representation of a Python string
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"""
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if _PY3:
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if isinstance(s, binary_type):
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s = s.decode('utf-8')
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else:
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if isinstance(s, str) and HAS_UTF8.search(s) is not None:
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s = s.decode('utf-8')
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def replace(match):
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return ESCAPE_DCT[match.group(0)]
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return _q + ESCAPE.sub(replace, s) + _q
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def py_encode_basestring_ascii(s, _PY3=PY3):
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"""Return an ASCII-only JSON representation of a Python string
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"""
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if _PY3:
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if isinstance(s, binary_type):
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s = s.decode('utf-8')
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else:
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if isinstance(s, str) and HAS_UTF8.search(s) is not None:
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s = s.decode('utf-8')
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def replace(match):
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s = match.group(0)
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try:
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return ESCAPE_DCT[s]
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except KeyError:
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n = ord(s)
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if n < 0x10000:
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#return '\\u{0:04x}'.format(n)
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return '\\u%04x' % (n,)
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else:
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# surrogate pair
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n -= 0x10000
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s1 = 0xd800 | ((n >> 10) & 0x3ff)
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s2 = 0xdc00 | (n & 0x3ff)
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#return '\\u{0:04x}\\u{1:04x}'.format(s1, s2)
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return '\\u%04x\\u%04x' % (s1, s2)
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return '"' + str(ESCAPE_ASCII.sub(replace, s)) + '"'
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encode_basestring_ascii = (
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c_encode_basestring_ascii or py_encode_basestring_ascii)
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class JSONEncoder(object):
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"""Extensible JSON <http://json.org> encoder for Python data structures.
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Supports the following objects and types by default:
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+-------------------+---------------+
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| Python | JSON |
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+===================+===============+
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| dict, namedtuple | object |
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+-------------------+---------------+
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| list, tuple | array |
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+-------------------+---------------+
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| str, unicode | string |
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+-------------------+---------------+
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| int, long, float | number |
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+-------------------+---------------+
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| True | true |
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+-------------------+---------------+
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| False | false |
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+-------------------+---------------+
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| None | null |
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+-------------------+---------------+
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To extend this to recognize other objects, subclass and implement a
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``.default()`` method with another method that returns a serializable
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object for ``o`` if possible, otherwise it should call the superclass
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implementation (to raise ``TypeError``).
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"""
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item_separator = ', '
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key_separator = ': '
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def __init__(self, skipkeys=False, ensure_ascii=True,
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check_circular=True, allow_nan=True, sort_keys=False,
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indent=None, separators=None, encoding='utf-8', default=None,
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use_decimal=True, namedtuple_as_object=True,
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tuple_as_array=True, bigint_as_string=False,
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item_sort_key=None):
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"""Constructor for JSONEncoder, with sensible defaults.
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If skipkeys is false, then it is a TypeError to attempt
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encoding of keys that are not str, int, long, float or None. If
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skipkeys is True, such items are simply skipped.
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If ensure_ascii is true, the output is guaranteed to be str
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objects with all incoming unicode characters escaped. If
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ensure_ascii is false, the output will be unicode object.
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If check_circular is true, then lists, dicts, and custom encoded
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objects will be checked for circular references during encoding to
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prevent an infinite recursion (which would cause an OverflowError).
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Otherwise, no such check takes place.
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If allow_nan is true, then NaN, Infinity, and -Infinity will be
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encoded as such. This behavior is not JSON specification compliant,
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but is consistent with most JavaScript based encoders and decoders.
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Otherwise, it will be a ValueError to encode such floats.
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If sort_keys is true, then the output of dictionaries will be
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sorted by key; this is useful for regression tests to ensure
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that JSON serializations can be compared on a day-to-day basis.
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If indent is a string, then JSON array elements and object members
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will be pretty-printed with a newline followed by that string repeated
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for each level of nesting. ``None`` (the default) selects the most compact
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representation without any newlines. For backwards compatibility with
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versions of simplejson earlier than 2.1.0, an integer is also accepted
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and is converted to a string with that many spaces.
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If specified, separators should be a (item_separator, key_separator)
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tuple. The default is (', ', ': '). To get the most compact JSON
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representation you should specify (',', ':') to eliminate whitespace.
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If specified, default is a function that gets called for objects
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that can't otherwise be serialized. It should return a JSON encodable
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version of the object or raise a ``TypeError``.
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If encoding is not None, then all input strings will be
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transformed into unicode using that encoding prior to JSON-encoding.
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The default is UTF-8.
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If use_decimal is true (not the default), ``decimal.Decimal`` will
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be supported directly by the encoder. For the inverse, decode JSON
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with ``parse_float=decimal.Decimal``.
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If namedtuple_as_object is true (the default), objects with
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``_asdict()`` methods will be encoded as JSON objects.
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If tuple_as_array is true (the default), tuple (and subclasses) will
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be encoded as JSON arrays.
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If bigint_as_string is true (not the default), ints 2**53 and higher
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or lower than -2**53 will be encoded as strings. This is to avoid the
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rounding that happens in Javascript otherwise.
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If specified, item_sort_key is a callable used to sort the items in
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each dictionary. This is useful if you want to sort items other than
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in alphabetical order by key.
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"""
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self.skipkeys = skipkeys
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self.ensure_ascii = ensure_ascii
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self.check_circular = check_circular
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self.allow_nan = allow_nan
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self.sort_keys = sort_keys
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self.use_decimal = use_decimal
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self.namedtuple_as_object = namedtuple_as_object
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self.tuple_as_array = tuple_as_array
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self.bigint_as_string = bigint_as_string
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self.item_sort_key = item_sort_key
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if indent is not None and not isinstance(indent, string_types):
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indent = indent * ' '
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self.indent = indent
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if separators is not None:
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self.item_separator, self.key_separator = separators
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elif indent is not None:
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self.item_separator = ','
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if default is not None:
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self.default = default
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self.encoding = encoding
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def default(self, o):
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"""Implement this method in a subclass such that it returns
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a serializable object for ``o``, or calls the base implementation
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(to raise a ``TypeError``).
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For example, to support arbitrary iterators, you could
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implement default like this::
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def default(self, o):
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try:
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iterable = iter(o)
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except TypeError:
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pass
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else:
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return list(iterable)
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return JSONEncoder.default(self, o)
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"""
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raise TypeError(repr(o) + " is not JSON serializable")
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def encode(self, o):
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"""Return a JSON string representation of a Python data structure.
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>>> from simplejson import JSONEncoder
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>>> JSONEncoder().encode({"foo": ["bar", "baz"]})
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'{"foo": ["bar", "baz"]}'
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"""
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# This is for extremely simple cases and benchmarks.
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if isinstance(o, binary_type):
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_encoding = self.encoding
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if (_encoding is not None and not (_encoding == 'utf-8')):
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o = o.decode(_encoding)
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if isinstance(o, string_types):
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if self.ensure_ascii:
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return encode_basestring_ascii(o)
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else:
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return encode_basestring(o)
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# This doesn't pass the iterator directly to ''.join() because the
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# exceptions aren't as detailed. The list call should be roughly
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# equivalent to the PySequence_Fast that ''.join() would do.
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chunks = self.iterencode(o, _one_shot=True)
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if not isinstance(chunks, (list, tuple)):
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chunks = list(chunks)
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if self.ensure_ascii:
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return ''.join(chunks)
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else:
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return u''.join(chunks)
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def iterencode(self, o, _one_shot=False):
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"""Encode the given object and yield each string
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representation as available.
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For example::
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for chunk in JSONEncoder().iterencode(bigobject):
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mysocket.write(chunk)
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"""
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if self.check_circular:
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markers = {}
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else:
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markers = None
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if self.ensure_ascii:
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_encoder = encode_basestring_ascii
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else:
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_encoder = encode_basestring
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if self.encoding != 'utf-8':
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def _encoder(o, _orig_encoder=_encoder, _encoding=self.encoding):
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if isinstance(o, binary_type):
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o = o.decode(_encoding)
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return _orig_encoder(o)
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def floatstr(o, allow_nan=self.allow_nan,
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_repr=FLOAT_REPR, _inf=PosInf, _neginf=-PosInf):
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# Check for specials. Note that this type of test is processor
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# and/or platform-specific, so do tests which don't depend on
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# the internals.
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if o != o:
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text = 'NaN'
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elif o == _inf:
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text = 'Infinity'
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elif o == _neginf:
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text = '-Infinity'
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else:
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return _repr(o)
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if not allow_nan:
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raise ValueError(
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"Out of range float values are not JSON compliant: " +
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repr(o))
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return text
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key_memo = {}
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if (_one_shot and c_make_encoder is not None
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and self.indent is None):
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_iterencode = c_make_encoder(
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markers, self.default, _encoder, self.indent,
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self.key_separator, self.item_separator, self.sort_keys,
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self.skipkeys, self.allow_nan, key_memo, self.use_decimal,
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self.namedtuple_as_object, self.tuple_as_array,
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self.bigint_as_string, self.item_sort_key,
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self.encoding,
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Decimal)
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else:
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_iterencode = _make_iterencode(
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markers, self.default, _encoder, self.indent, floatstr,
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self.key_separator, self.item_separator, self.sort_keys,
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self.skipkeys, _one_shot, self.use_decimal,
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self.namedtuple_as_object, self.tuple_as_array,
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self.bigint_as_string, self.item_sort_key,
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self.encoding,
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Decimal=Decimal)
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try:
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return _iterencode(o, 0)
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finally:
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key_memo.clear()
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class JSONEncoderForHTML(JSONEncoder):
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"""An encoder that produces JSON safe to embed in HTML.
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To embed JSON content in, say, a script tag on a web page, the
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characters &, < and > should be escaped. They cannot be escaped
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with the usual entities (e.g. &) because they are not expanded
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within <script> tags.
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"""
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def encode(self, o):
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# Override JSONEncoder.encode because it has hacks for
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# performance that make things more complicated.
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chunks = self.iterencode(o, True)
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if self.ensure_ascii:
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return ''.join(chunks)
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else:
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return u''.join(chunks)
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def iterencode(self, o, _one_shot=False):
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chunks = super(JSONEncoderForHTML, self).iterencode(o, _one_shot)
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for chunk in chunks:
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chunk = chunk.replace('&', '\\u0026')
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chunk = chunk.replace('<', '\\u003c')
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chunk = chunk.replace('>', '\\u003e')
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yield chunk
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def _make_iterencode(markers, _default, _encoder, _indent, _floatstr,
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_key_separator, _item_separator, _sort_keys, _skipkeys, _one_shot,
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_use_decimal, _namedtuple_as_object, _tuple_as_array,
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_bigint_as_string, _item_sort_key, _encoding,
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## HACK: hand-optimized bytecode; turn globals into locals
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_PY3=PY3,
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ValueError=ValueError,
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string_types=string_types,
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Decimal=Decimal,
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dict=dict,
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float=float,
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id=id,
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integer_types=integer_types,
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isinstance=isinstance,
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list=list,
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str=str,
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tuple=tuple,
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):
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if _item_sort_key and not callable(_item_sort_key):
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raise TypeError("item_sort_key must be None or callable")
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elif _sort_keys and not _item_sort_key:
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_item_sort_key = itemgetter(0)
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def _iterencode_list(lst, _current_indent_level):
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if not lst:
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yield '[]'
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return
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if markers is not None:
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markerid = id(lst)
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if markerid in markers:
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raise ValueError("Circular reference detected")
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markers[markerid] = lst
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buf = '['
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if _indent is not None:
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_current_indent_level += 1
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newline_indent = '\n' + (_indent * _current_indent_level)
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separator = _item_separator + newline_indent
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buf += newline_indent
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else:
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newline_indent = None
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separator = _item_separator
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first = True
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for value in lst:
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if first:
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first = False
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else:
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buf = separator
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if (isinstance(value, string_types) or
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(_PY3 and isinstance(value, binary_type))):
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yield buf + _encoder(value)
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elif value is None:
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yield buf + 'null'
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elif value is True:
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yield buf + 'true'
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elif value is False:
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yield buf + 'false'
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elif isinstance(value, integer_types):
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yield ((buf + str(value))
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if (not _bigint_as_string or
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(-1 << 53) < value < (1 << 53))
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else (buf + '"' + str(value) + '"'))
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elif isinstance(value, float):
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yield buf + _floatstr(value)
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elif _use_decimal and isinstance(value, Decimal):
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yield buf + str(value)
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else:
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yield buf
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if isinstance(value, list):
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chunks = _iterencode_list(value, _current_indent_level)
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else:
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_asdict = _namedtuple_as_object and getattr(value, '_asdict', None)
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if _asdict and callable(_asdict):
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chunks = _iterencode_dict(_asdict(),
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_current_indent_level)
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elif _tuple_as_array and isinstance(value, tuple):
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chunks = _iterencode_list(value, _current_indent_level)
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elif isinstance(value, dict):
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chunks = _iterencode_dict(value, _current_indent_level)
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else:
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chunks = _iterencode(value, _current_indent_level)
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for chunk in chunks:
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yield chunk
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if newline_indent is not None:
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_current_indent_level -= 1
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yield '\n' + (_indent * _current_indent_level)
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yield ']'
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if markers is not None:
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del markers[markerid]
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def _stringify_key(key):
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if isinstance(key, string_types): # pragma: no cover
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pass
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elif isinstance(key, binary_type):
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key = key.decode(_encoding)
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elif isinstance(key, float):
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key = _floatstr(key)
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elif key is True:
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key = 'true'
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elif key is False:
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key = 'false'
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elif key is None:
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key = 'null'
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elif isinstance(key, integer_types):
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key = str(key)
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elif _use_decimal and isinstance(key, Decimal):
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key = str(key)
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elif _skipkeys:
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key = None
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else:
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raise TypeError("key " + repr(key) + " is not a string")
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return key
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def _iterencode_dict(dct, _current_indent_level):
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if not dct:
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yield '{}'
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return
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if markers is not None:
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markerid = id(dct)
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if markerid in markers:
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raise ValueError("Circular reference detected")
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markers[markerid] = dct
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yield '{'
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if _indent is not None:
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_current_indent_level += 1
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newline_indent = '\n' + (_indent * _current_indent_level)
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item_separator = _item_separator + newline_indent
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yield newline_indent
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else:
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newline_indent = None
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item_separator = _item_separator
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first = True
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if _PY3:
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iteritems = dct.items()
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else:
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iteritems = dct.iteritems()
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if _item_sort_key:
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items = []
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for k, v in dct.items():
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if not isinstance(k, string_types):
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k = _stringify_key(k)
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if k is None:
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continue
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items.append((k, v))
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items.sort(key=_item_sort_key)
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else:
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items = iteritems
|
|
for key, value in items:
|
|
if not (_item_sort_key or isinstance(key, string_types)):
|
|
key = _stringify_key(key)
|
|
if key is None:
|
|
# _skipkeys must be True
|
|
continue
|
|
if first:
|
|
first = False
|
|
else:
|
|
yield item_separator
|
|
yield _encoder(key)
|
|
yield _key_separator
|
|
if (isinstance(value, string_types) or
|
|
(_PY3 and isinstance(value, binary_type))):
|
|
yield _encoder(value)
|
|
elif value is None:
|
|
yield 'null'
|
|
elif value is True:
|
|
yield 'true'
|
|
elif value is False:
|
|
yield 'false'
|
|
elif isinstance(value, integer_types):
|
|
yield (str(value)
|
|
if (not _bigint_as_string or
|
|
(-1 << 53) < value < (1 << 53))
|
|
else ('"' + str(value) + '"'))
|
|
elif isinstance(value, float):
|
|
yield _floatstr(value)
|
|
elif _use_decimal and isinstance(value, Decimal):
|
|
yield str(value)
|
|
else:
|
|
if isinstance(value, list):
|
|
chunks = _iterencode_list(value, _current_indent_level)
|
|
else:
|
|
_asdict = _namedtuple_as_object and getattr(value, '_asdict', None)
|
|
if _asdict and callable(_asdict):
|
|
chunks = _iterencode_dict(_asdict(),
|
|
_current_indent_level)
|
|
elif _tuple_as_array and isinstance(value, 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)
|
|
for chunk in chunks:
|
|
yield chunk
|
|
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, string_types) or
|
|
(_PY3 and isinstance(o, binary_type))):
|
|
yield _encoder(o)
|
|
elif o is None:
|
|
yield 'null'
|
|
elif o is True:
|
|
yield 'true'
|
|
elif o is False:
|
|
yield 'false'
|
|
elif isinstance(o, integer_types):
|
|
yield (str(o)
|
|
if (not _bigint_as_string or
|
|
(-1 << 53) < o < (1 << 53))
|
|
else ('"' + str(o) + '"'))
|
|
elif isinstance(o, float):
|
|
yield _floatstr(o)
|
|
elif isinstance(o, list):
|
|
for chunk in _iterencode_list(o, _current_indent_level):
|
|
yield chunk
|
|
else:
|
|
_asdict = _namedtuple_as_object and getattr(o, '_asdict', None)
|
|
if _asdict and callable(_asdict):
|
|
for chunk in _iterencode_dict(_asdict(), _current_indent_level):
|
|
yield chunk
|
|
elif (_tuple_as_array and isinstance(o, tuple)):
|
|
for chunk in _iterencode_list(o, _current_indent_level):
|
|
yield chunk
|
|
elif isinstance(o, dict):
|
|
for chunk in _iterencode_dict(o, _current_indent_level):
|
|
yield chunk
|
|
elif _use_decimal and isinstance(o, Decimal):
|
|
yield str(o)
|
|
else:
|
|
if markers is not None:
|
|
markerid = id(o)
|
|
if markerid in markers:
|
|
raise ValueError("Circular reference detected")
|
|
markers[markerid] = o
|
|
o = _default(o)
|
|
for chunk in _iterencode(o, _current_indent_level):
|
|
yield chunk
|
|
if markers is not None:
|
|
del markers[markerid]
|
|
|
|
return _iterencode
|