| """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 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,)) |
| |
| # Assume this produces an infinity on all machines (probably not guaranteed) |
| INFINITY = float('1e66666') |
| FLOAT_REPR = repr |
| |
| def 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) + '"' |
| |
| |
| 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 a (item_separator, key_separator) |
| tuple. The default is (', ', ': '). 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 |
| 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) |
| return JSONEncoder.default(self, o) |
| |
| """ |
| raise TypeError(repr(o) + " is not JSON serializable") |
| |
| def encode(self, o): |
| """Return a JSON string representation of a Python data structure. |
| |
| >>> 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 not self.indent): |
| _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, |
| ): |
| |
| 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): |
| yield buf + str(value) |
| elif isinstance(value, float): |
| 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) |
| 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_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): |
| 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): |
| key = str(key) |
| elif _skipkeys: |
| continue |
| else: |
| raise TypeError("key " + repr(key) + " is not a string") |
| 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): |
| yield str(value) |
| elif isinstance(value, float): |
| 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) |
| 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, 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): |
| yield str(o) |
| elif isinstance(o, float): |
| yield _floatstr(o) |
| elif isinstance(o, (list, 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 |
| 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 |