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Python

# Copyright 2015 Google Inc. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import enum
import math
import re
from typing import (
Any,
Callable,
IO,
Iterable,
Mapping,
Optional,
Set,
Tuple,
Type,
Union,
)
import unicodedata
from json5.parser import Parser
# Used when encoding keys, below.
_reserved_word_re: Optional[re.Pattern] = None
class QuoteStyle(enum.Enum):
"""Controls how strings will be quoted during encoding.
By default, for compatibility with the `json` module and older versions of
`json5`, strings (not being used as keys and that are legal identifiers)
will always be double-quoted, and any double quotes in the string will be
escaped. This is `QuoteStyle.ALWAYS_DOUBLE`. If you pass
`QuoteStyle.ALWAYS_SINGLE`, then strings will always be single-quoted, and
any single quotes in the string will be escaped. If you pass
`QuoteStyle.PREFER_DOUBLE`, then the behavior is the same as ALWAYS_DOUBLE
and strings will be double-quoted *unless* the string contains more double
quotes than single quotes, in which case the string will be single-quoted
and single quotes will be escaped. If you pass `QuoteStyle.PREFER_SINGLE`,
then the behavior is the same as ALWAYS_SINGLE and strings will be
single-quoted *unless* the string contains more single quotes than double
quotes, in which case the string will be double-quoted and any double
quotes will be escaped.
*Note:* PREFER_DOUBLE and PREFER_SINGLE can impact performance, since in
order to know which encoding to use you have to iterate over the entire
string to count the number of single and double quotes. The codes guesses
at an encoding while doing so, but if it guess wrong, the entire string has
to be re-encoded, which will slow things down. If you are very concerned
about performance (a) you probably shouldn't be using this library in the
first place, because it just isn't very fast, and (b) you should use
ALWAYS_DOUBLE or ALWAYS_SINGLE, which won't have this issue.
"""
ALWAYS_DOUBLE = 'always_double'
ALWAYS_SINGLE = 'always_single'
PREFER_DOUBLE = 'prefer_double'
PREFER_SINGLE = 'prefer_single'
def load(
fp: IO,
*,
encoding: Optional[str] = None,
cls: Any = None,
object_hook: Optional[Callable[[Mapping[str, Any]], Any]] = None,
parse_float: Optional[Callable[[str], Any]] = None,
parse_int: Optional[Callable[[str], Any]] = None,
parse_constant: Optional[Callable[[str], Any]] = None,
strict: bool = True,
object_pairs_hook: Optional[
Callable[[Iterable[Tuple[str, Any]]], Any]
] = None,
allow_duplicate_keys: bool = True,
consume_trailing: bool = True,
start: Optional[int] = None,
) -> Any:
"""Deserialize ``fp`` (a ``.read()``-supporting file-like object
containing a JSON document) to a Python object.
Supports almost the same arguments as ``json.load()`` except that:
- the `cls` keyword is ignored.
- an extra `allow_duplicate_keys` parameter supports checking for
duplicate keys in a object; by default, this is True for
compatibility with ``json.load()``, but if set to False and
the object contains duplicate keys, a ValueError will be raised.
- an extra `consume_trailing` parameter specifies whether to
consume any trailing characters after a valid object has been
parsed. By default, this value is True and the only legal
trailing characters are whitespace. If this value is set to False,
parsing will stop when a valid object has been parsed and any
trailing characters in the string will be ignored.
- an extra `start` parameter specifies the zero-based offset into the
file to start parsing at. If `start` is None, parsing will
start at the current position in the file, and line number
and column values will be reported as if starting from the
beginning of the file; If `start` is not None,
`load` will seek to zero and then read (and discard) the
appropriate number of characters before beginning parsing;
the file must be seekable for this to work correctly.
You can use `load(..., consume_trailing=False)` to repeatedly read
values from a file. However, in the current implementation `load` does
this by reading the entire file into memory before doing anything, so
it is not very efficient.
Raises
- `ValueError` if given an invalid document. This is different
from the `json` module, which raises `json.JSONDecodeError`.
- `UnicodeDecodeError` if given a byte string that is not a
legal UTF-8 document (or the equivalent, if using a different
`encoding`). This matches the `json` module.
"""
s = fp.read()
val, err, _ = parse(
s,
encoding=encoding,
cls=cls,
object_hook=object_hook,
parse_float=parse_float,
parse_int=parse_int,
parse_constant=parse_constant,
strict=strict,
object_pairs_hook=object_pairs_hook,
allow_duplicate_keys=allow_duplicate_keys,
consume_trailing=consume_trailing,
start=start,
)
if err:
raise ValueError(err)
return val
def loads(
s: str,
*,
encoding: Optional[str] = None,
cls: Any = None,
object_hook: Optional[Callable[[Mapping[str, Any]], Any]] = None,
parse_float: Optional[Callable[[str], Any]] = None,
parse_int: Optional[Callable[[str], Any]] = None,
parse_constant: Optional[Callable[[str], Any]] = None,
strict: bool = True,
object_pairs_hook: Optional[
Callable[[Iterable[Tuple[str, Any]]], Any]
] = None,
allow_duplicate_keys: bool = True,
consume_trailing: bool = True,
start: Optional[int] = None,
):
"""Deserialize ``s`` (a string containing a JSON5 document) to a Python
object.
Supports the same arguments as ``json.load()`` except that:
- the `cls` keyword is ignored.
- an extra `allow_duplicate_keys` parameter supports checking for
duplicate keys in a object; by default, this is True for
compatibility with ``json.load()``, but if set to False and
the object contains duplicate keys, a ValueError will be raised.
- an extra `consume_trailing` parameter specifies whether to
consume any trailing characters after a valid object has been
parsed. By default, this value is True and the only legal
trailing characters are whitespace. If this value is set to False,
parsing will stop when a valid object has been parsed and any
trailing characters in the string will be ignored.
- an extra `start` parameter specifies the zero-based offset into the
string to start parsing at.
Raises
- `ValueError` if given an invalid document. This is different
from the `json` module, which raises `json.JSONDecodeError`.
- `UnicodeDecodeError` if given a byte string that is not a
legal UTF-8 document (or the equivalent, if using a different
`encoding`). This matches the `json` module.
"""
val, err, _ = parse(
s=s,
encoding=encoding,
cls=cls,
object_hook=object_hook,
parse_float=parse_float,
parse_int=parse_int,
parse_constant=parse_constant,
strict=strict,
object_pairs_hook=object_pairs_hook,
allow_duplicate_keys=allow_duplicate_keys,
consume_trailing=consume_trailing,
start=start,
)
if err:
raise ValueError(err)
return val
def parse(
s: str,
*,
encoding: Optional[str] = None,
cls: Any = None,
object_hook: Optional[Callable[[Mapping[str, Any]], Any]] = None,
parse_float: Optional[Callable[[str], Any]] = None,
parse_int: Optional[Callable[[str], Any]] = None,
parse_constant: Optional[Callable[[str], Any]] = None,
strict: bool = True,
object_pairs_hook: Optional[
Callable[[Iterable[Tuple[str, Any]]], Any]
] = None,
allow_duplicate_keys: bool = True,
consume_trailing: bool = True,
start: Optional[int] = None,
):
"""Parse ```s``, returning positional information along with a value.
This works exactly like `loads()`, except that (a) it returns the
position in the string where the parsing stopped (either due to
hitting an error or parsing a valid value) and any error as a string,
(b) it takes an optional `consume_trailing` parameter that says whether
to keep parsing the string after a valid value has been parsed; if True
(the default), any trailing characters must be whitespace. If False,
parsing stops when a valid value has been reached, (c) it takes an
optional `start` parameter that specifies a zero-based offset to start
parsing from in the string, and (d) the return value is different, as
described below.
`parse()` is useful if you have a string that might contain multiple
values and you need to extract all of them; you can do so by repeatedly
calling `parse`, setting `start` to the value returned in `position`
from the previous call.
Returns a tuple of (value, error_string, position). If the string
was a legal value, `value` will be the deserialized value,
`error_string` will be `None`, and `position` will be one
past the zero-based offset where the parser stopped reading.
If the string was not a legal value,
`value` will be `None`, `error_string` will be the string value
of the exception that would've been raised, and `position` will
be the zero-based farthest offset into the string where the parser
hit an error.
Raises:
- `UnicodeDecodeError` if given a byte string that is not a
legal UTF-8 document (or the equivalent, if using a different
`encoding`). This matches the `json` module.
Note that this does *not* raise a `ValueError`; instead any error is
returned as the second value in the tuple.
You can use this method to read in a series of values from a string
`s` as follows:
>>> import json5
>>> s = '1 2 3 4'
>>> values = []
>>> start = 0
>>> while True:
... v, err, pos = json5.parse(s, start=start, consume_trailing=False)
... if v:
... values.append(v)
... start = pos
... if start == len(s) or s[start:].isspace():
... # Reached the end of the string (ignoring trailing
... # whitespace
... break
... continue
... raise ValueError(err)
>>> values
[1, 2, 3, 4]
"""
assert cls is None, 'Custom decoders are not supported'
if isinstance(s, bytes):
encoding = encoding or 'utf-8'
s = s.decode(encoding)
if not s:
raise ValueError('Empty strings are not legal JSON5')
start = start or 0
parser = Parser(s, '<string>', pos=start)
ast, err, pos = parser.parse(
global_vars={'_strict': strict, '_consume_trailing': consume_trailing}
)
if err:
return None, err, pos
try:
value = _convert(
ast,
object_hook=object_hook,
parse_float=parse_float,
parse_int=parse_int,
parse_constant=parse_constant,
object_pairs_hook=object_pairs_hook,
allow_duplicate_keys=allow_duplicate_keys,
)
return value, None, pos
except ValueError as e:
return None, str(e), pos
def _convert(
ast,
object_hook,
parse_float,
parse_int,
parse_constant,
object_pairs_hook,
allow_duplicate_keys,
):
def _fp_constant_parser(s):
return float(s.replace('Infinity', 'inf').replace('NaN', 'nan'))
def _dictify(pairs):
if not allow_duplicate_keys:
keys = set()
for key, _ in pairs:
if key in keys:
raise ValueError(f'Duplicate key "{key}" found in object')
keys.add(key)
if object_pairs_hook:
return object_pairs_hook(pairs)
if object_hook:
return object_hook(dict(pairs))
return dict(pairs)
parse_float = parse_float or float
parse_int = parse_int or int
parse_constant = parse_constant or _fp_constant_parser
return _walk_ast(ast, _dictify, parse_float, parse_int, parse_constant)
def _walk_ast(
el,
dictify: Callable[[Iterable[Tuple[str, Any]]], Any],
parse_float,
parse_int,
parse_constant,
):
if el == 'None':
return None
if el == 'True':
return True
if el == 'False':
return False
ty, v = el
if ty == 'number':
if v.startswith('0x') or v.startswith('0X'):
return parse_int(v, base=16)
if '.' in v or 'e' in v or 'E' in v:
return parse_float(v)
if 'Infinity' in v or 'NaN' in v:
return parse_constant(v)
return parse_int(v)
if ty == 'string':
return v
if ty == 'object':
pairs = []
for key, val_expr in v:
val = _walk_ast(
val_expr, dictify, parse_float, parse_int, parse_constant
)
pairs.append((key, val))
return dictify(pairs)
if ty == 'array':
return [
_walk_ast(el, dictify, parse_float, parse_int, parse_constant)
for el in v
]
raise ValueError('unknown el: ' + el) # pragma: no cover
def dump(
obj: Any,
fp: IO,
*,
skipkeys: bool = False,
ensure_ascii: bool = True,
check_circular: bool = True,
allow_nan: bool = True,
cls: Optional[Type['JSON5Encoder']] = None,
indent: Optional[Union[int, str]] = None,
separators: Optional[Tuple[str, str]] = None,
default: Optional[Callable[[Any], Any]] = None,
sort_keys: bool = False,
quote_keys: bool = False,
trailing_commas: bool = True,
allow_duplicate_keys: bool = True,
quote_style: QuoteStyle = QuoteStyle.ALWAYS_DOUBLE,
**kw,
):
"""Serialize ``obj`` to a JSON5-formatted stream to ``fp``,
a ``.write()``-supporting file-like object.
Supports the same arguments as ``dumps()``, below.
Calling ``dump(obj, fp, quote_keys=True, trailing_commas=False, \
allow_duplicate_keys=True)``
should produce exactly the same output as ``json.dump(obj, fp).``
"""
fp.write(
dumps(
obj=obj,
skipkeys=skipkeys,
ensure_ascii=ensure_ascii,
check_circular=check_circular,
allow_nan=allow_nan,
cls=cls,
indent=indent,
separators=separators,
default=default,
sort_keys=sort_keys,
quote_keys=quote_keys,
trailing_commas=trailing_commas,
allow_duplicate_keys=allow_duplicate_keys,
quote_style=quote_style,
**kw,
)
)
def dumps(
obj: Any,
*,
skipkeys: bool = False,
ensure_ascii: bool = True,
check_circular: bool = True,
allow_nan: bool = True,
cls: Optional[Type['JSON5Encoder']] = None,
indent: Optional[Union[int, str]] = None,
separators: Optional[Tuple[str, str]] = None,
default: Optional[Callable[[Any], Any]] = None,
sort_keys: bool = False,
quote_keys: bool = False,
trailing_commas: bool = True,
allow_duplicate_keys: bool = True,
quote_style: QuoteStyle = QuoteStyle.ALWAYS_DOUBLE,
**kw,
):
"""Serialize ``obj`` to a JSON5-formatted string.
Supports the same arguments as ``json.dumps()``, except that:
- The ``encoding`` keyword is ignored; Unicode strings are always written.
- By default, object keys that are legal identifiers are not quoted; if you
pass ``quote_keys=True``, they will be.
- By default, if lists and objects span multiple lines of output (i.e.,
when ``indent`` >=0), the last item will have a trailing comma after it.
If you pass ``trailing_commas=False``, it will not.
- If you use a number, a boolean, or ``None`` as a key value in a dict, it
will be converted to the corresponding JSON string value, e.g. "1",
"true", or "null". By default, ``dump()`` will match the `json` modules
behavior and produce malformed JSON if you mix keys of different types
that have the same converted value; e.g., ``{1: "foo", "1": "bar"}``
produces '{"1": "foo", "1": "bar"}', an object with duplicated keys. If
you pass ``allow_duplicate_keys=False``, an exception will be raised
instead.
- If `quote_keys` is true, then keys of objects will be enclosed in quotes,
as in regular JSON. Otheriwse, keys will not be enclosed in quotes unless
they contain whitespace.
- If `trailing_commas` is false, then commas will not be inserted after the
final elements of objects and arrays, as in regular JSON. Otherwise,
such commas will be inserted.
- If `allow_duplicate_keys` is false, then only the last entry with a given
key will be written. Otherwise, all entries with the same key will be
written.
- `quote_style` controls how strings are encoded. See the documentation
for the `QuoteStyle` class, above, for how this is used.
*Note*: Strings that are being used as unquoted keys are not affected
by this parameter and remain unquoted.
*`quote_style` was added in version 0.10.0*.
Other keyword arguments are allowed and will be passed to the
encoder so custom encoders can get them, but otherwise they will
be ignored in an attempt to provide some amount of forward-compatibility.
*Note:* the standard JSON module explicitly calls `int.__repr(obj)__`
and `float.__repr(obj)__` to encode ints and floats, thereby bypassing
any custom representations you might have for objects that are subclasses
of ints and floats, and, for compatibility, JSON5 does the same thing.
To override this behavior, create a subclass of JSON5Encoder
that overrides `encode()` and handles your custom representation.
For example:
```
>>> import json5
>>> from typing import Any, Set
>>>
>>> class Hex(int):
... def __repr__(self):
... return hex(self)
>>>
>>> class CustomEncoder(json5.JSON5Encoder):
... def encode(
... self, obj: Any, seen: Set, level: int, *, as_key: bool
... ) -> str:
... if isinstance(obj, Hex):
... return repr(obj)
... return super().encode(obj, seen, level, as_key=as_key)
...
>>> json5.dumps([20, Hex(20)], cls=CustomEncoder)
'[20, 0x14]'
```
*Note:* calling ``dumps(obj, quote_keys=True, trailing_commas=False, \
allow_duplicate_keys=True)``
should produce exactly the same output as ``json.dumps(obj).``
"""
cls = cls or JSON5Encoder
enc = cls(
skipkeys=skipkeys,
ensure_ascii=ensure_ascii,
check_circular=check_circular,
allow_nan=allow_nan,
indent=indent,
separators=separators,
default=default,
sort_keys=sort_keys,
quote_keys=quote_keys,
trailing_commas=trailing_commas,
allow_duplicate_keys=allow_duplicate_keys,
quote_style=quote_style,
**kw,
)
return enc.encode(obj, seen=set(), level=0, as_key=False)
class JSON5Encoder:
def __init__(
self,
*,
skipkeys: bool = False,
ensure_ascii: bool = True,
check_circular: bool = True,
allow_nan: bool = True,
indent: Optional[Union[int, str]] = None,
separators: Optional[Tuple[str, str]] = None,
default: Optional[Callable[[Any], Any]] = None,
sort_keys: bool = False,
quote_keys: bool = False,
trailing_commas: bool = True,
allow_duplicate_keys: bool = True,
quote_style: QuoteStyle = QuoteStyle.ALWAYS_DOUBLE,
**kw,
):
"""Provides a class that may be overridden to customize the behavior
of `dumps()`. The keyword args are the same as for that function.
*Added in version 0.10.0"""
# Ignore unrecognized keyword arguments in the hope of providing
# some level of backwards- and forwards-compatibility.
del kw
self.skipkeys = skipkeys
self.ensure_ascii = ensure_ascii
self.check_circular = check_circular
self.allow_nan = allow_nan
self.indent = indent
self.separators = separators
if separators is None:
separators = (', ', ': ') if indent is None else (',', ': ')
self.item_separator, self.kv_separator = separators
self.default_fn = default or _raise_type_error
self.sort_keys = sort_keys
self.quote_keys = quote_keys
self.trailing_commas = trailing_commas
self.allow_duplicate_keys = allow_duplicate_keys
self.quote_style = quote_style
def default(self, obj: Any) -> Any:
"""Provides a last-ditch option to encode a value that the encoder
doesn't otherwise recognize, by converting `obj` to a value that
*can* (and will) be serialized by the other methods in the class.
Note: this must not return a serialized value (i.e., string)
directly, as that'll result in a doubly-encoded value."""
return self.default_fn(obj)
def encode(
self,
obj: Any,
seen: Set,
level: int,
*,
as_key: bool,
) -> str:
"""Returns an JSON5-encoded version of an arbitrary object. This can
be used to provide customized serialization of objects. Overridden
methods of this class should handle their custom objects and then
fall back to super.encode() if they've been passed a normal object.
`seen` is used for duplicate object tracking when `check_circular`
is True.
`level` represents the current indentation level, which increases
by one for each recursive invocation of encode (i.e., whenever
we're encoding the values of a dict or a list).
May raise `TypeError` if the object is the wrong type to be
encoded (i.e., your custom routine can't handle it either), and
`ValueError` if there's something wrong with the value, e.g.
a float value of NaN when `allow_nan` is false.
If `as_key` is true, the return value should be a double-quoted string
representation of the object, unless obj is a string that can be an
identifier (and quote_keys is false and obj isn't a reserved word).
If the object should not be used as a key, `TypeError` should be
raised; that allows the base implementation to implement `skipkeys`
properly.
"""
seen = seen or set()
s = self._encode_basic_type(obj, as_key=as_key)
if s is not None:
return s
if as_key:
raise TypeError(f'Invalid key f{obj}')
return self._encode_non_basic_type(obj, seen, level)
def _encode_basic_type(self, obj: Any, *, as_key: bool) -> Optional[str]:
"""Returns None if the object is not a basic type."""
if isinstance(obj, str):
return self._encode_str(obj, as_key=as_key)
# Check for True/False before ints because True and False are
# also considered ints and so would be represented as 1 and 0
# if we did ints first.
if obj is True:
return '"true"' if as_key else 'true'
if obj is False:
return '"false"' if as_key else 'false'
if obj is None:
return '"null"' if as_key else 'null'
if isinstance(obj, int):
return self._encode_int(obj, as_key=as_key)
if isinstance(obj, float):
return self._encode_float(obj, as_key=as_key)
return None
def _encode_int(self, obj: int, *, as_key: bool) -> str:
s = int.__repr__(obj)
return f'"{s}"' if as_key else s
def _encode_float(self, obj: float, *, as_key: bool) -> str:
if obj == float('inf'):
allowed = self.allow_nan
s = 'Infinity'
elif obj == float('-inf'):
allowed = self.allow_nan
s = '-Infinity'
elif math.isnan(obj):
allowed = self.allow_nan
s = 'NaN'
else:
allowed = True
s = float.__repr__(obj)
if not allowed:
raise ValueError('Illegal JSON5 value: f{obj}')
return f'"{s}"' if as_key else s
def _encode_str(self, obj: str, *, as_key: bool) -> str:
if (
as_key
and self.is_identifier(obj)
and not self.quote_keys
and not self.is_reserved_word(obj)
):
return obj
return self._encode_quoted_str(obj, self.quote_style)
def _encode_quoted_str(self, obj: str, quote_style: QuoteStyle) -> str:
"""Returns a quoted string with a minimal number of escaped quotes."""
ret = []
double_quotes_seen = 0
single_quotes_seen = 0
sq = "'"
dq = '"'
for ch in obj:
if ch == dq:
# At first we will guess at which quotes to escape. If
# we guess wrong, we reencode the string below.
double_quotes_seen += 1
if quote_style in (
QuoteStyle.ALWAYS_DOUBLE,
QuoteStyle.PREFER_DOUBLE,
):
encoded_ch = self._escape_ch(dq)
else:
encoded_ch = dq
elif ch == sq:
single_quotes_seen += 1
if quote_style in (
QuoteStyle.ALWAYS_SINGLE,
QuoteStyle.PREFER_SINGLE,
):
encoded_ch = self._escape_ch(sq)
else:
encoded_ch = sq
elif ch == '\\':
encoded_ch = self._escape_ch(ch)
else:
o = ord(ch)
if o < 32:
encoded_ch = self._escape_ch(ch)
elif o < 128:
encoded_ch = ch
elif not self.ensure_ascii and ch not in ('\u2028', '\u2029'):
encoded_ch = ch
else:
encoded_ch = self._escape_ch(ch)
ret.append(encoded_ch)
# We may have guessed wrong and need to reencode the string.
if (
double_quotes_seen > single_quotes_seen
and quote_style == QuoteStyle.PREFER_DOUBLE
):
return self._encode_quoted_str(obj, QuoteStyle.ALWAYS_SINGLE)
if (
single_quotes_seen > double_quotes_seen
and quote_style == QuoteStyle.PREFER_SINGLE
):
return self._encode_quoted_str(obj, QuoteStyle.ALWAYS_DOUBLE)
if quote_style in (QuoteStyle.ALWAYS_DOUBLE, QuoteStyle.PREFER_DOUBLE):
return '"' + ''.join(ret) + '"'
return "'" + ''.join(ret) + "'"
def _escape_ch(self, ch: str) -> str:
"""Returns the backslash-escaped representation of the char."""
if ch == '\\':
return '\\\\'
if ch == "'":
return r'\''
if ch == '"':
return r'\"'
if ch == '\n':
return r'\n'
if ch == '\r':
return r'\r'
if ch == '\t':
return r'\t'
if ch == '\b':
return r'\b'
if ch == '\f':
return r'\f'
if ch == '\v':
return r'\v'
if ch == '\0':
return r'\0'
o = ord(ch)
if o < 65536:
return rf'\u{o:04x}'
val = o - 0x10000
high = 0xD800 + (val >> 10)
low = 0xDC00 + (val & 0x3FF)
return rf'\u{high:04x}\u{low:04x}'
def _encode_non_basic_type(self, obj, seen: Set, level: int) -> str:
# Basic types can't be recursive so we only check for circularity
# on non-basic types. If for some reason the caller was using a
# subclass of a basic type and wanted to check circularity on it,
# it'd have to do so directly in a subclass of JSON5Encoder.
if self.check_circular:
i = id(obj)
if i in seen:
raise ValueError('Circular reference detected.')
seen.add(i)
# Ideally we'd use collections.abc.Mapping and collections.abc.Sequence
# here, but for backwards-compatibility with potential old callers,
# we only check for the two attributes we need in each case.
if hasattr(obj, 'keys') and hasattr(obj, '__getitem__'):
s = self._encode_dict(obj, seen, level + 1)
elif hasattr(obj, '__getitem__') and hasattr(obj, '__iter__'):
s = self._encode_array(obj, seen, level + 1)
else:
s = self.encode(self.default(obj), seen, level, as_key=False)
assert s is not None
if self.check_circular:
seen.remove(i)
return s
def _encode_dict(self, obj: Any, seen: set, level: int) -> str:
if not obj:
return '{}'
indent_str, end_str = self._spacers(level)
item_sep = self.item_separator + indent_str
kv_sep = self.kv_separator
if self.sort_keys:
keys = sorted(obj.keys())
else:
keys = obj.keys()
s = '{' + indent_str
first_key = True
new_keys = set()
for key in keys:
try:
key_str = self.encode(key, seen, level, as_key=True)
except TypeError:
if self.skipkeys:
continue
raise
if not self.allow_duplicate_keys:
if key_str in new_keys:
raise ValueError(f'duplicate key {repr(key)}')
new_keys.add(key_str)
if first_key:
first_key = False
else:
s += item_sep
val_str = self.encode(obj[key], seen, level, as_key=False)
s += key_str + kv_sep + val_str
s += end_str + '}'
return s
def _encode_array(self, obj: Any, seen: Set, level: int) -> str:
if not obj:
return '[]'
indent_str, end_str = self._spacers(level)
item_sep = self.item_separator + indent_str
return (
'['
+ indent_str
+ item_sep.join(
self.encode(el, seen, level, as_key=False) for el in obj
)
+ end_str
+ ']'
)
def _spacers(self, level: int) -> Tuple[str, str]:
if self.indent is not None:
end_str = ''
if self.trailing_commas:
end_str = ','
if isinstance(self.indent, int):
if self.indent > 0:
indent_str = '\n' + ' ' * self.indent * level
end_str += '\n' + ' ' * self.indent * (level - 1)
else:
indent_str = '\n'
end_str += '\n'
else:
indent_str = '\n' + self.indent * level
end_str += '\n' + self.indent * (level - 1)
else:
indent_str = ''
end_str = ''
return indent_str, end_str
def is_identifier(self, key: str) -> bool:
"""Returns whether the string could be used as a legal
EcmaScript/JavaScript identifier.
There should normally be no reason to override this, unless
the definition of identifiers change in later versions of the
JSON5 spec and this implementation hasn't been updated to handle
the changes yet."""
if (
not key
or not self._is_id_start(key[0])
and key[0] not in ('$', '_')
):
return False
for ch in key[1:]:
if not self._is_id_continue(ch) and ch not in ('$', '_'):
return False
return True
def _is_id_start(self, ch: str) -> bool:
return unicodedata.category(ch) in (
'Lu',
'Ll',
'Li',
'Lt',
'Lm',
'Lo',
'Nl',
)
def _is_id_continue(self, ch: str) -> bool:
return unicodedata.category(ch) in (
'Lu',
'Ll',
'Li',
'Lt',
'Lm',
'Lo',
'Nl',
'Nd',
'Mn',
'Mc',
'Pc',
)
def is_reserved_word(self, key: str) -> bool:
"""Returns whether the key is a reserved word.
There should normally be no need to override this, unless there
have been reserved words added in later versions of the JSON5
spec and this implementation has not yet been updated to handle
the changes yet."""
global _reserved_word_re
if _reserved_word_re is None:
# List taken from section 7.6.1 of ECMA-262, version 5.1.
# https://262.ecma-international.org/5.1/#sec-7.6.1.
# This includes currently reserved words, words reserved
# for future use (both as of 5.1), null, true, and false.
_reserved_word_re = re.compile(
'('
+ '|'.join(
[
'break',
'case',
'catch',
'class',
'const',
'continue',
'debugger',
'default',
'delete',
'do',
'else',
'enum',
'export',
'extends',
'false',
'finally',
'for',
'function',
'if',
'implements',
'import',
'in',
'instanceof',
'interface',
'let',
'new',
'null',
'package',
'private',
'protected',
'public',
'return',
'static',
'super',
'switch',
'this',
'throw',
'true',
'try',
'typeof',
'var',
'void',
'while',
'with',
'yield',
]
)
+ ')$'
)
return _reserved_word_re.match(key) is not None
def _raise_type_error(obj) -> Any:
raise TypeError(f'{repr(obj)} is not JSON5 serializable')