PyJSON5¶

A JSON5 serializer and parser library for Python 3 written in Cython.

The serializer returns ASCII data that can safely be used in an HTML template. Apostrophes, ampersands, greater-than, and less-then signs are encoded as unicode escaped sequences. E.g. this snippet is safe for any and all input:

"<a onclick='alert(" + encode(data) + ")'>show message</a>"

Unless the input contains infinite or NaN values, the result will be valid JSON data.

All valid JSON5 1.0.0 and JSON data can be read, unless the nesting level is absurdly high.

→ Glossary / Index

Function summary¶

`decode`(data[, maxdepth, some])	Decodes JSON5 serialized data from an `str` object.
`decode_buffer`(obj[, maxdepth, some, wordlength])	Decodes JSON5 serialized data from an object that supports the buffer protocol, e.g.
`decode_callback`(cb[, maxdepth, some, args])	Decodes JSON5 serialized data by invoking a callback.
`decode_io`(fp[, maxdepth, some])	Decodes JSON5 serialized data from a file-like object.
`decode_latin1`(data[, maxdepth, some])	Decodes JSON5 serialized data from a `bytes` object.
`dump`(obj, fp, **kw)	Serializes a Python object to a JSON5 compatible unicode string.
`dumps`(obj, **kw)	Serializes a Python object to a JSON5 compatible unicode string.
`encode`(data, *[, options])	Serializes a Python object to a JSON5 compatible unicode string.
`encode_bytes`(data, *[, options])	Serializes a Python object to a JSON5 compatible bytes string.
`encode_callback`(data, cb[, supply_bytes, …])	Serializes a Python object into a callback function.
`encode_io`(data, fp[, supply_bytes, options])	Serializes a Python object into a file-object.
`encode_noop`(data, *[, options])	Test if the input is serializable.
`load`(fp, **kw)	Decodes JSON5 serialized data from a file-like object.
`loads`(s, *[, encoding])	Decodes JSON5 serialized data from a string.

Class / exception summary¶

Full description¶

pyjson5.decode(data, maxdepth=None, some=False)¶

Decodes JSON5 serialized data from an str object.

decode('["Hello", "world!"]') == ['Hello', 'world!']

Parameters:	data (unicode) – JSON5 serialized data maxdepth (Optional[int]) – Maximum nesting level before are the parsing is aborted. If `None` is supplied, then the value of the global variable `DEFAULT_MAX_NESTING_LEVEL` is used instead. If the value is `0`, then only literals are accepted, e.g. `false`, `47.11`, or `"string"`. If the value is negative, then the any nesting level is allowed until Python’s recursion limit is hit. some (bool) – Allow trailing junk.
Raises:	`Json5DecoderException` – An exception occured while decoding. `TypeError` – An argument had a wrong type.
Returns:	Deserialized data.
Return type:	object

pyjson5.decode_latin1(data, maxdepth=None, some=False)¶

Decodes JSON5 serialized data from a bytes object.

decode_buffer(b'["Hello", "world!"]') == ['Hello', 'world!']

Parameters:	data (bytes) – JSON5 serialized data, encoded as Latin-1 or ASCII. maxdepth (Optional[int]) – see decode(…) some (bool) – see decode(…)
Raises:	`Json5DecoderException` – An exception occured while decoding. `TypeError` – An argument had a wrong type.
Returns:	see decode(…)
Return type:	object

pyjson5.decode_buffer(obj, maxdepth=None, some=False, wordlength=None)¶

Decodes JSON5 serialized data from an object that supports the buffer protocol, e.g. bytearray.

obj = memoryview(b'["Hello", "world!"]')

decode_buffer(obj) == ['Hello', 'world!']

Parameters:	data (object) – JSON5 serialized data. The argument must support Python’s buffer protocol, i.e. `memoryview(...)` must work. The buffer must be contigious. maxdepth (Optional[int]) – see decode(…) some (bool) – see decode(…) wordlength (Optional[int]) – Must be 1, 2, 4 to denote UCS1, USC2 or USC4 data. Surrogates are not supported. Decode the data to an `str` if need be. If `None` is supplied, then the buffer’s `itemsize` is used.
Raises:	`Json5DecoderException` – An exception occured while decoding. `TypeError` – An argument had a wrong type. `ValueError` – The value of `wordlength` was invalid.
Returns:	see decode(…)
Return type:	object

pyjson5.decode_callback(cb, maxdepth=None, some=False, args=None)¶

Decodes JSON5 serialized data by invoking a callback.

cb = iter('["Hello","world!"]').__next__

decode_callback(cb) == ['Hello', 'world!']

Parameters:	cb (Callable[Any, Union[str\|bytes\|bytearray\|int\|None]]) – A function to get values from. The functions is called like `cb(args)`, and it returns: str, bytes, bytearray:* `len(...) == 0` denotes exhausted input. `len(...) == 1` is the next character. int: `< 0` denotes exhausted input. `>= 0` is the ordinal value of the next character. None: input exhausted maxdepth (Optional[int]) – see decode(…) some (bool) – see decode(…) args (Optional[Iterable[Any]]) – Arguments to call `cb` with.
Raises:	`Json5DecoderException` – An exception occured while decoding. `TypeError` – An argument had a wrong type.
Returns:	see `decode(...)`
Return type:	object

pyjson5.decode_io(fp, maxdepth=None, some=True)¶

Decodes JSON5 serialized data from a file-like object.

fp = io.StringIO("""
    ['Hello', /* TODO look into specs whom to greet */]
    'Wolrd' // FIXME: look for typos
""")

decode_io(fp) == ['Hello']
decode_io(fp) == 'Wolrd'

fp.seek(0)

decode_io(fp, some=False)
# raises Json5ExtraData('Extra data U+0027 near 56', ['Hello'], "'")

Parameters:	fp (IOBase) – A file-like object to parse from. maxdepth (Optional[int] = None) – see decode(…) some (bool) – see decode(…)
Raises:	`Json5DecoderException` – An exception occured while decoding. `TypeError` – An argument had a wrong type.
Returns:	see `decode(...)`
Return type:	object

pyjson5.encode(data, *, options=None, **options_kw)¶

Serializes a Python object to a JSON5 compatible unicode string.

encode(['Hello', 'world!']) == '["Hello","world!"]'

Parameters:	data (object) – Python object to serialize. options (Optional[Options]) – Extra options for the encoder. If `options` and `options_kw` are specified, then `options.update(options_kw)` is used. options_kw** – See Option’s arguments.
Raises:	`Json5EncoderException` – An exception occured while encoding. `TypeError` – An argument had a wrong type.
Returns:	Unless `float('inf')` or `float('nan')` is encountered, the result will be valid JSON data (as of RFC8259). The result is always ASCII. All characters outside of the ASCII range are encoded. The result safe to use in an HTML template, e.g. `<a onclick='alert({{ encode(url) }})'>show message</a>`. Apostrophes `"'"` are encoded as `"\u0027"`, less-than, greater-than, and ampersand likewise.
Return type:	str

pyjson5.encode_bytes(data, *, options=None, **options_kw)¶

Serializes a Python object to a JSON5 compatible bytes string.

encode_bytes(['Hello', 'world!']) == b'["Hello","world!"]'

Parameters:	data (object) – see encode(…) options (Optional[Options]) – see encode(…) options_kw – see encode(…)
Raises:	`Json5EncoderException` – An exception occured while encoding. `TypeError` – An argument had a wrong type.
Returns:	see encode(…)
Return type:	bytes

pyjson5.encode_callback(data, cb, supply_bytes=False, *, options=None, **options_kw)¶

Serializes a Python object into a callback function.

The callback function cb gets called with single characters and strings until the input data is fully serialized.

encode_callback(['Hello', 'world!'], print)
#prints:
# [
# "
# Hello
# "
# ,
# "
# world!
# "
" ]

Parameters:	data (object) – see encode(…) cb (Callable[[Union[bytes\|str]], None]) – A callback function. Depending on the truthyness of `supply_bytes` either `bytes` or `str` is supplied. supply_bytes (bool) – Call `cb(...)` with a `bytes` argument if true, otherwise `str`. options (Optional[Options]) – see encode(…) options_kw – see encode(…)
Raises:	`Json5EncoderException` – An exception occured while encoding. `TypeError` – An argument had a wrong type.
Returns:	The supplied argument `cb`.
Return type:	Callable[[Union[bytes\|str]], None]

pyjson5.encode_io(data, fp, supply_bytes=True, *, options=None, **options_kw)¶

Serializes a Python object into a file-object.

The return value of fp.write(...) is not checked. If fp is unbuffered, then the result will be garbage!

Parameters:	data (object) – see encode(…) fp (IOBase) – A file-like object to serialize into. supply_bytes (bool) – Call `fp.write(...)` with a `bytes` argument if true, otherwise `str`. options (Optional[Options]) – see encode(…) options_kw – see encode(…)
Raises:	`Json5EncoderException` – An exception occured while encoding. `TypeError` – An argument had a wrong type.
Returns:	The supplied argument `fp`.
Return type:	IOBase

pyjson5.encode_noop(data, *, options=None, **options_kw)¶

Test if the input is serializable.

Most likely you want to serialize data directly, and catch exceptions instead of using this function!

encode_noop({47: 11}) == True
encode_noop({47: object()}) == False

Parameters:	data (object) – see encode(…) options (Optional[Options]) – see encode(…) options_kw – see encode(…)
Returns:	`True` iff `data` is serializable.
Return type:	bool

class pyjson5.Options¶

Customizations for the encoder_*(...) function family.

Immutable. Use Options.update(**kw) to create a new Options instance.

Parameters:

tojson (str|False|None) –
- str: A special method to call on objects to return a custom JSON encoded string. Must return ASCII data!
- False: No such member exists. (Default.)
- None: Use default.
posinfinity (str|False|None) –
- str: String to represent positive infinity. Must be ASCII.
- False: Throw an exception if float('+inf') is encountered.
- None: Use default: "Infinity".
neginfinity (str|False|None) –
- str: String to represent negative infinity. Must be ASCII.
- False: Throw an exception if float('-inf') is encountered.
- None: Use default: "-Infinity".
nan (str|False|None) –
- str: String to represent not-a-number. Must be ASCII.
- False: Throw an exception if float('NaN') is encountered.
- None: Use default: "NaN".
intformat (str|False|None) –
- str: Format string to use with int.
- False: Throw an exception if an int is encountered.
- None: Use default: "%d".
floatformat (str|False|None) –
- str: Format string to use with float.
- False: Throw an exception if a float is encountered.
- None: Use default: "%.6e".
decimalformat (str|False|None) –
- str: Format string to use with Decimal.
- False: Throw an exception if a Decimal is encountered.
- None: Use default: "%s".
mappingtypes (Iterable[type]|False|None) –
- Iterable[type]: Classes the should be encoded to objects. Must be iterable over their keys, and implement __getitem__.
- False: There are no objects. Any object will be encoded as list of key-value tuples.
- None: Use default: [collections.abc.Mapping].

decimalformat¶: The creation argument decimalformat. None if False was specified.

floatformat¶: The creation argument floatformat. None if False was specified.

intformat¶: The creation argument intformat. None if False was specified.

mappingtypes¶: The creation argument mappingtypes. () if False was specified.

nan¶: The creation argument nan. None if False was specified.

neginfinity¶: The creation argument neginfinity. None if False was specified.

posinfinity¶: The creation argument posinfinity. None if False was specified.

tojson¶: The creation argument tojson. None if False was specified.

update(self, **kw)¶: Creates a new Options instance by modifying some members.

pyjson5.loads(s, *, encoding='UTF-8', **kw)¶

Decodes JSON5 serialized data from a string.

Use decode(…) instead!

loads(s) == decode(s)

Parameters:	s (object) – Unless the argument is an `str`, it gets decoded according to the parameter `encoding`. encoding (str) – Codec to use if `s` is not an `str`. kw – Silently ignored.
Returns:	see `decode(...)`
Return type:	object

pyjson5.load(fp, **kw)¶

Decodes JSON5 serialized data from a file-like object.

Use decode_io(…) instead!

load(fp) == decode_io(fp, None, False)

Parameters:	fp (IOBase) – A file-like object to parse from. kw – Silently ignored.
Returns:	see `decode(...)`
Return type:	object

pyjson5.dumps(obj, **kw)¶

Serializes a Python object to a JSON5 compatible unicode string.

Use encode(…) instead!

dumps(obj) == encode(obj)

Parameters:	obj (object) – Python object to serialize. kw – Silently ignored.
Returns:	see `encode(data)`
Return type:	unicode

pyjson5.dump(obj, fp, **kw)¶

Serializes a Python object to a JSON5 compatible unicode string.

Use encode_io(…) instead!

dump(obj, fp) == encode_io(obj, fp)

Parameters:	obj (object) – Python object to serialize. fp (IOBase) – A file-like object to serialize into. kw – Silently ignored.

exception pyjson5.Json5Exception(message=None, *args)¶

Base class of any exception thrown by PyJSON5.

message¶: Human readable error description

with_traceback()¶: Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception pyjson5.Json5EncoderException¶

Base class of any exception thrown by the serializer.

message¶: Human readable error description

with_traceback()¶: Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception pyjson5.Json5UnstringifiableType(message=None, unstringifiable=None)¶

The encoder was not able to stringify the input, or it was told not to by the supplied Options.

message¶: Human readable error description

unstringifiable¶: The value that caused the problem.

with_traceback()¶: Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception pyjson5.Json5DecoderException(message=None, result=None, *args)¶

Base class of any exception thrown by the parser.

message¶: Human readable error description

result¶: Deserialized data up until now.

with_traceback()¶: Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception pyjson5.Json5NestingTooDeep¶

The maximum nesting level on the input data was exceeded.

message¶: Human readable error description

result¶: Deserialized data up until now.

with_traceback()¶: Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception pyjson5.Json5EOF¶

The input ended prematurely.

message¶: Human readable error description

result¶: Deserialized data up until now.

with_traceback()¶: Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception pyjson5.Json5IllegalCharacter(message=None, result=None, character=None, *args)¶

An unexpected character was encountered.

character¶: Extranous character.

message¶: Human readable error description

result¶: Deserialized data up until now.

with_traceback()¶: Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception pyjson5.Json5ExtraData(message=None, result=None, character=None, *args)¶

The input contained extranous data.

character¶: Extranous character.

message¶: Human readable error description

result¶: Deserialized data up until now.

with_traceback()¶: Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception pyjson5.Json5IllegalType(message=None, result=None, value=None, *args)¶

The user supplied callback function returned illegal data.

message¶: Human readable error description

result¶: Deserialized data up until now.

value¶: Value that caused the problem.

with_traceback()¶: Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.