mirror of
git://projects.qi-hardware.com/openwrt-packages.git
synced 2024-11-23 13:04:40 +02:00
385 lines
13 KiB
Python
385 lines
13 KiB
Python
"""Implementation of JSONEncoder
|
|
"""
|
|
|
|
import re
|
|
import math
|
|
|
|
try:
|
|
from _json import encode_basestring_ascii as c_encode_basestring_ascii
|
|
except ImportError:
|
|
c_encode_basestring_ascii = None
|
|
|
|
__all__ = ['JSONEncoder']
|
|
|
|
ESCAPE = re.compile(r'[\x00-\x1f\\"\b\f\n\r\t]')
|
|
ESCAPE_ASCII = re.compile(r'([\\"]|[^\ -~])')
|
|
HAS_UTF8 = re.compile(r'[\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))
|
|
|
|
FLOAT_REPR = repr
|
|
|
|
def floatstr(o, allow_nan=True):
|
|
# 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 math.isnan(o):
|
|
text = 'NaN'
|
|
elif math.isinf(o):
|
|
if math.copysign(1., o) == 1.:
|
|
text = 'Infinity'
|
|
else:
|
|
text = '-Infinity'
|
|
else:
|
|
return FLOAT_REPR(o)
|
|
|
|
if not allow_nan:
|
|
msg = "Out of range float values are not JSON compliant: " + repr(o)
|
|
raise ValueError(msg)
|
|
|
|
return text
|
|
|
|
|
|
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):
|
|
if isinstance(s, str) and HAS_UTF8.search(s) is not None:
|
|
s = s.decode('utf-8')
|
|
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)
|
|
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 '"' + str(ESCAPE_ASCII.sub(replace, s)) + '"'
|
|
|
|
|
|
if c_encode_basestring_ascii is not None:
|
|
encode_basestring_ascii = c_encode_basestring_ascii
|
|
else:
|
|
encode_basestring_ascii = 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, unicode | string |
|
|
+-------------------+---------------+
|
|
| int, long, 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``).
|
|
|
|
"""
|
|
__all__ = ['__init__', 'default', 'encode', 'iterencode']
|
|
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, encoding='utf-8', 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, long, 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 unicode characters escaped. If
|
|
ensure_ascii is false, the output will be unicode object.
|
|
|
|
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``.
|
|
|
|
If encoding is not None, then all input strings will be
|
|
transformed into unicode using that encoding prior to JSON-encoding.
|
|
The default is UTF-8.
|
|
|
|
"""
|
|
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
|
|
self.current_indent_level = 0
|
|
if separators is not None:
|
|
self.item_separator, self.key_separator = separators
|
|
if default is not None:
|
|
self.default = default
|
|
self.encoding = encoding
|
|
|
|
def _newline_indent(self):
|
|
return '\n' + (' ' * (self.indent * self.current_indent_level))
|
|
|
|
def _iterencode_list(self, lst, markers=None):
|
|
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
|
|
yield '['
|
|
if self.indent is not None:
|
|
self.current_indent_level += 1
|
|
newline_indent = self._newline_indent()
|
|
separator = self.item_separator + newline_indent
|
|
yield newline_indent
|
|
else:
|
|
newline_indent = None
|
|
separator = self.item_separator
|
|
first = True
|
|
for value in lst:
|
|
if first:
|
|
first = False
|
|
else:
|
|
yield separator
|
|
for chunk in self._iterencode(value, markers):
|
|
yield chunk
|
|
if newline_indent is not None:
|
|
self.current_indent_level -= 1
|
|
yield self._newline_indent()
|
|
yield ']'
|
|
if markers is not None:
|
|
del markers[markerid]
|
|
|
|
def _iterencode_dict(self, dct, markers=None):
|
|
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 '{'
|
|
key_separator = self.key_separator
|
|
if self.indent is not None:
|
|
self.current_indent_level += 1
|
|
newline_indent = self._newline_indent()
|
|
item_separator = self.item_separator + newline_indent
|
|
yield newline_indent
|
|
else:
|
|
newline_indent = None
|
|
item_separator = self.item_separator
|
|
first = True
|
|
if self.ensure_ascii:
|
|
encoder = encode_basestring_ascii
|
|
else:
|
|
encoder = encode_basestring
|
|
allow_nan = self.allow_nan
|
|
if self.sort_keys:
|
|
keys = dct.keys()
|
|
keys.sort()
|
|
items = [(k, dct[k]) for k in keys]
|
|
else:
|
|
items = dct.iteritems()
|
|
_encoding = self.encoding
|
|
_do_decode = (_encoding is not None
|
|
and not (_encoding == 'utf-8'))
|
|
for key, value in items:
|
|
if isinstance(key, str):
|
|
if _do_decode:
|
|
key = key.decode(_encoding)
|
|
elif isinstance(key, basestring):
|
|
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, allow_nan)
|
|
elif isinstance(key, (int, long)):
|
|
key = str(key)
|
|
elif key is True:
|
|
key = 'true'
|
|
elif key is False:
|
|
key = 'false'
|
|
elif key is None:
|
|
key = 'null'
|
|
elif self.skipkeys:
|
|
continue
|
|
else:
|
|
raise TypeError("key {0!r} is not a string".format(key))
|
|
if first:
|
|
first = False
|
|
else:
|
|
yield item_separator
|
|
yield encoder(key)
|
|
yield key_separator
|
|
for chunk in self._iterencode(value, markers):
|
|
yield chunk
|
|
if newline_indent is not None:
|
|
self.current_indent_level -= 1
|
|
yield self._newline_indent()
|
|
yield '}'
|
|
if markers is not None:
|
|
del markers[markerid]
|
|
|
|
def _iterencode(self, o, markers=None):
|
|
if isinstance(o, basestring):
|
|
if self.ensure_ascii:
|
|
encoder = encode_basestring_ascii
|
|
else:
|
|
encoder = encode_basestring
|
|
_encoding = self.encoding
|
|
if (_encoding is not None and isinstance(o, str)
|
|
and not (_encoding == 'utf-8')):
|
|
o = o.decode(_encoding)
|
|
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, long)):
|
|
yield str(o)
|
|
elif isinstance(o, float):
|
|
yield floatstr(o, self.allow_nan)
|
|
elif isinstance(o, (list, tuple)):
|
|
for chunk in self._iterencode_list(o, markers):
|
|
yield chunk
|
|
elif isinstance(o, dict):
|
|
for chunk in self._iterencode_dict(o, markers):
|
|
yield chunk
|
|
else:
|
|
if markers is not None:
|
|
markerid = id(o)
|
|
if markerid in markers:
|
|
raise ValueError("Circular reference detected")
|
|
markers[markerid] = o
|
|
for chunk in self._iterencode_default(o, markers):
|
|
yield chunk
|
|
if markers is not None:
|
|
del markers[markerid]
|
|
|
|
def _iterencode_default(self, o, markers=None):
|
|
newobj = self.default(o)
|
|
return self._iterencode(newobj, markers)
|
|
|
|
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, basestring):
|
|
if isinstance(o, str):
|
|
_encoding = self.encoding
|
|
if (_encoding is not None
|
|
and not (_encoding == 'utf-8')):
|
|
o = o.decode(_encoding)
|
|
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 = list(self.iterencode(o))
|
|
return ''.join(chunks)
|
|
|
|
def iterencode(self, o):
|
|
"""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
|
|
return self._iterencode(o, markers)
|