-"""Implementation of JSONDecoder
-"""
-from __future__ import absolute_import
-import re
-import sys
-import struct
-from .compat import fromhex, b, u, text_type, binary_type, PY3, unichr
-from .scanner import make_scanner, JSONDecodeError
-
-def _import_c_scanstring():
- try:
- from ._speedups import scanstring
- return scanstring
- except ImportError:
- return None
-c_scanstring = _import_c_scanstring()
-
-# NOTE (3.1.0): JSONDecodeError may still be imported from this module for
-# compatibility, but it was never in the __all__
-__all__ = ['JSONDecoder']
-
-FLAGS = re.VERBOSE | re.MULTILINE | re.DOTALL
-
-def _floatconstants():
- _BYTES = fromhex('7FF80000000000007FF0000000000000')
- # The struct module in Python 2.4 would get frexp() out of range here
- # when an endian is specified in the format string. Fixed in Python 2.5+
- if sys.byteorder != 'big':
- _BYTES = _BYTES[:8][::-1] + _BYTES[8:][::-1]
- nan, inf = struct.unpack('dd', _BYTES)
- return nan, inf, -inf
-
-NaN, PosInf, NegInf = _floatconstants()
-
-_CONSTANTS = {
- '-Infinity': NegInf,
- 'Infinity': PosInf,
- 'NaN': NaN,
-}
-
-STRINGCHUNK = re.compile(r'(.*?)(["\\\x00-\x1f])', FLAGS)
-BACKSLASH = {
- '"': u('"'), '\\': u('\u005c'), '/': u('/'),
- 'b': u('\b'), 'f': u('\f'), 'n': u('\n'), 'r': u('\r'), 't': u('\t'),
-}
-
-DEFAULT_ENCODING = "utf-8"
-
-def py_scanstring(s, end, encoding=None, strict=True,
- _b=BACKSLASH, _m=STRINGCHUNK.match, _join=u('').join,
- _PY3=PY3, _maxunicode=sys.maxunicode):
- """Scan the string s for a JSON string. End is the index of the
- character in s after the quote that started the JSON string.
- Unescapes all valid JSON string escape sequences and raises ValueError
- on attempt to decode an invalid string. If strict is False then literal
- control characters are allowed in the string.
-
- Returns a tuple of the decoded string and the index of the character in s
- after the end quote."""
- if encoding is None:
- encoding = DEFAULT_ENCODING
- chunks = []
- _append = chunks.append
- begin = end - 1
- while 1:
- chunk = _m(s, end)
- if chunk is None:
- raise JSONDecodeError(
- "Unterminated string starting at", s, begin)
- end = chunk.end()
- content, terminator = chunk.groups()
- # Content is contains zero or more unescaped string characters
- if content:
- if not _PY3 and not isinstance(content, text_type):
- content = text_type(content, encoding)
- _append(content)
- # Terminator is the end of string, a literal control character,
- # or a backslash denoting that an escape sequence follows
- if terminator == '"':
- break
- elif terminator != '\\':
- if strict:
- msg = "Invalid control character %r at"
- raise JSONDecodeError(msg, s, end)
- else:
- _append(terminator)
- continue
- try:
- esc = s[end]
- except IndexError:
- raise JSONDecodeError(
- "Unterminated string starting at", s, begin)
- # If not a unicode escape sequence, must be in the lookup table
- if esc != 'u':
- try:
- char = _b[esc]
- except KeyError:
- msg = "Invalid \\X escape sequence %r"
- raise JSONDecodeError(msg, s, end)
- end += 1
- else:
- # Unicode escape sequence
- msg = "Invalid \\uXXXX escape sequence"
- esc = s[end + 1:end + 5]
- escX = esc[1:2]
- if len(esc) != 4 or escX == 'x' or escX == 'X':
- raise JSONDecodeError(msg, s, end - 1)
- try:
- uni = int(esc, 16)
- except ValueError:
- raise JSONDecodeError(msg, s, end - 1)
- end += 5
- # Check for surrogate pair on UCS-4 systems
- # Note that this will join high/low surrogate pairs
- # but will also pass unpaired surrogates through
- if (_maxunicode > 65535 and
- uni & 0xfc00 == 0xd800 and
- s[end:end + 2] == '\\u'):
- esc2 = s[end + 2:end + 6]
- escX = esc2[1:2]
- if len(esc2) == 4 and not (escX == 'x' or escX == 'X'):
- try:
- uni2 = int(esc2, 16)
- except ValueError:
- raise JSONDecodeError(msg, s, end)
- if uni2 & 0xfc00 == 0xdc00:
- uni = 0x10000 + (((uni - 0xd800) << 10) |
- (uni2 - 0xdc00))
- end += 6
- char = unichr(uni)
- # Append the unescaped character
- _append(char)
- return _join(chunks), end
-
-
-# Use speedup if available
-scanstring = c_scanstring or py_scanstring
-
-WHITESPACE = re.compile(r'[ \t\n\r]*', FLAGS)
-WHITESPACE_STR = ' \t\n\r'
-
-def JSONObject(state, encoding, strict, scan_once, object_hook,
- object_pairs_hook, memo=None,
- _w=WHITESPACE.match, _ws=WHITESPACE_STR):
- (s, end) = state
- # Backwards compatibility
- if memo is None:
- memo = {}
- memo_get = memo.setdefault
- pairs = []
- # Use a slice to prevent IndexError from being raised, the following
- # check will raise a more specific ValueError if the string is empty
- nextchar = s[end:end + 1]
- # Normally we expect nextchar == '"'
- if nextchar != '"':
- if nextchar in _ws:
- end = _w(s, end).end()
- nextchar = s[end:end + 1]
- # Trivial empty object
- if nextchar == '}':
- if object_pairs_hook is not None:
- result = object_pairs_hook(pairs)
- return result, end + 1
- pairs = {}
- if object_hook is not None:
- pairs = object_hook(pairs)
- return pairs, end + 1
- elif nextchar != '"':
- raise JSONDecodeError(
- "Expecting property name enclosed in double quotes",
- s, end)
- end += 1
- while True:
- key, end = scanstring(s, end, encoding, strict)
- key = memo_get(key, key)
-
- # To skip some function call overhead we optimize the fast paths where
- # the JSON key separator is ": " or just ":".
- if s[end:end + 1] != ':':
- end = _w(s, end).end()
- if s[end:end + 1] != ':':
- raise JSONDecodeError("Expecting ':' delimiter", s, end)
-
- end += 1
-
- try:
- if s[end] in _ws:
- end += 1
- if s[end] in _ws:
- end = _w(s, end + 1).end()
- except IndexError:
- pass
-
- value, end = scan_once(s, end)
- pairs.append((key, value))
-
- try:
- nextchar = s[end]
- if nextchar in _ws:
- end = _w(s, end + 1).end()
- nextchar = s[end]
- except IndexError:
- nextchar = ''
- end += 1
-
- if nextchar == '}':
- break
- elif nextchar != ',':
- raise JSONDecodeError("Expecting ',' delimiter or '}'", s, end - 1)
-
- try:
- nextchar = s[end]
- if nextchar in _ws:
- end += 1
- nextchar = s[end]
- if nextchar in _ws:
- end = _w(s, end + 1).end()
- nextchar = s[end]
- except IndexError:
- nextchar = ''
-
- end += 1
- if nextchar != '"':
- raise JSONDecodeError(
- "Expecting property name enclosed in double quotes",
- s, end - 1)
-
- if object_pairs_hook is not None:
- result = object_pairs_hook(pairs)
- return result, end
- pairs = dict(pairs)
- if object_hook is not None:
- pairs = object_hook(pairs)
- return pairs, end
-
-def JSONArray(state, scan_once, _w=WHITESPACE.match, _ws=WHITESPACE_STR):
- (s, end) = state
- values = []
- nextchar = s[end:end + 1]
- if nextchar in _ws:
- end = _w(s, end + 1).end()
- nextchar = s[end:end + 1]
- # Look-ahead for trivial empty array
- if nextchar == ']':
- return values, end + 1
- elif nextchar == '':
- raise JSONDecodeError("Expecting value or ']'", s, end)
- _append = values.append
- while True:
- value, end = scan_once(s, end)
- _append(value)
- nextchar = s[end:end + 1]
- if nextchar in _ws:
- end = _w(s, end + 1).end()
- nextchar = s[end:end + 1]
- end += 1
- if nextchar == ']':
- break
- elif nextchar != ',':
- raise JSONDecodeError("Expecting ',' delimiter or ']'", s, end - 1)
-
- try:
- if s[end] in _ws:
- end += 1
- if s[end] in _ws:
- end = _w(s, end + 1).end()
- except IndexError:
- pass
-
- return values, end
-
-class JSONDecoder(object):
- """Simple JSON <http://json.org> decoder
-
- Performs the following translations in decoding by default:
-
- +---------------+-------------------+
- | JSON | Python |
- +===============+===================+
- | object | dict |
- +---------------+-------------------+
- | array | list |
- +---------------+-------------------+
- | string | str, unicode |
- +---------------+-------------------+
- | number (int) | int, long |
- +---------------+-------------------+
- | number (real) | float |
- +---------------+-------------------+
- | true | True |
- +---------------+-------------------+
- | false | False |
- +---------------+-------------------+
- | null | None |
- +---------------+-------------------+
-
- It also understands ``NaN``, ``Infinity``, and ``-Infinity`` as
- their corresponding ``float`` values, which is outside the JSON spec.
-
- """
-
- def __init__(self, encoding=None, object_hook=None, parse_float=None,
- parse_int=None, parse_constant=None, strict=True,
- object_pairs_hook=None):
- """
- *encoding* determines the encoding used to interpret any
- :class:`str` objects decoded by this instance (``'utf-8'`` by
- default). It has no effect when decoding :class:`unicode` objects.
-
- Note that currently only encodings that are a superset of ASCII work,
- strings of other encodings should be passed in as :class:`unicode`.
-
- *object_hook*, if specified, will be called with the result of every
- JSON object decoded and its return value will be used in place of the
- given :class:`dict`. This can be used to provide custom
- deserializations (e.g. to support JSON-RPC class hinting).
-
- *object_pairs_hook* is an optional function that will be called with
- the result of any object literal decode with an ordered list of pairs.
- The return value of *object_pairs_hook* will be used instead of the
- :class:`dict`. This feature can be used to implement custom decoders
- that rely on the order that the key and value pairs are decoded (for
- example, :func:`collections.OrderedDict` will remember the order of
- insertion). If *object_hook* is also defined, the *object_pairs_hook*
- takes priority.
-
- *parse_float*, if specified, will be called with the string of every
- JSON float to be decoded. By default, this is equivalent to
- ``float(num_str)``. This can be used to use another datatype or parser
- for JSON floats (e.g. :class:`decimal.Decimal`).
-
- *parse_int*, if specified, will be called with the string of every
- JSON int to be decoded. By default, this is equivalent to
- ``int(num_str)``. This can be used to use another datatype or parser
- for JSON integers (e.g. :class:`float`).
-
- *parse_constant*, if specified, will be called with one of the
- following strings: ``'-Infinity'``, ``'Infinity'``, ``'NaN'``. This
- can be used to raise an exception if invalid JSON numbers are
- encountered.
-
- *strict* controls the parser's behavior when it encounters an
- invalid control character in a string. The default setting of
- ``True`` means that unescaped control characters are parse errors, if
- ``False`` then control characters will be allowed in strings.
-
- """
- if encoding is None:
- encoding = DEFAULT_ENCODING
- self.encoding = encoding
- self.object_hook = object_hook
- self.object_pairs_hook = object_pairs_hook
- self.parse_float = parse_float or float
- self.parse_int = parse_int or int
- self.parse_constant = parse_constant or _CONSTANTS.__getitem__
- self.strict = strict
- self.parse_object = JSONObject
- self.parse_array = JSONArray
- self.parse_string = scanstring
- self.memo = {}
- self.scan_once = make_scanner(self)
-
- def decode(self, s, _w=WHITESPACE.match, _PY3=PY3):
- """Return the Python representation of ``s`` (a ``str`` or ``unicode``
- instance containing a JSON document)
-
- """
- if _PY3 and isinstance(s, binary_type):
- s = s.decode(self.encoding)
- obj, end = self.raw_decode(s)
- end = _w(s, end).end()
- if end != len(s):
- raise JSONDecodeError("Extra data", s, end, len(s))
- return obj
-
- def raw_decode(self, s, idx=0, _w=WHITESPACE.match, _PY3=PY3):
- """Decode a JSON document from ``s`` (a ``str`` or ``unicode``
- beginning with a JSON document) and return a 2-tuple of the Python
- representation and the index in ``s`` where the document ended.
- Optionally, ``idx`` can be used to specify an offset in ``s`` where
- the JSON document begins.
-
- This can be used to decode a JSON document from a string that may
- have extraneous data at the end.
-
- """
- if _PY3 and not isinstance(s, text_type):
- raise TypeError("Input string must be text, not bytes")
- return self.scan_once(s, idx=_w(s, idx).end())
projects / wikipedia-api-cdsw / blobdiff