Smarter Json Library

Overridden JSON utilities for the Smarter platform.

This module wraps the standard json library with the following enhancements:

Uses SmarterJSONEncoder as the default encoder.
Standardizes indentation to 2 characters.
Falls back to str() for non-serializable objects.

SmarterJSONEncoder adds serialization support for the following types:

datetime.datetime, datetime.date, datetime.time, datetime.timedelta
decimal.Decimal
uuid.UUID
taggit.managers.TaggableManager

The following symbols are re-exported unmodified from json:

exception smarter.lib.json.JSONDecodeError(msg, doc, pos)[source]

Bases: ValueError

Subclass of ValueError with the following additional properties:

msg: The unformatted error message doc: The JSON document being parsed pos: The start index of doc where parsing failed lineno: The line corresponding to pos colno: The column corresponding to pos

__init__(msg, doc, pos)[source]

class smarter.lib.json.JSONDecoder(*, object_hook=None, parse_float=None, parse_int=None, parse_constant=None, strict=True, object_pairs_hook=None)[source]

Bases: object

Simple JSON <https://json.org> decoder

Performs the following translations in decoding by default:

JSON	Python
object	dict
array	list
string	str
number (int)	int
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.

__init__(*, object_hook=None, parse_float=None, parse_int=None, parse_constant=None, strict=True, object_pairs_hook=None)[source]

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 dict. This can be used to provide custom deserializations (e.g. to support JSON-RPC class hinting).

object_pairs_hook, if specified will be called with the result of every JSON object decoded with an ordered list of pairs. The return value of object_pairs_hook will be used instead of the dict. This feature can be used to implement custom decoders. 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. 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. 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.

If strict is false (true is the default), then control characters will be allowed inside strings. Control characters in this context are those with character codes in the 0-31 range, including '\t' (tab), '\n', '\r' and '\0'.

decode(s, _w=<built-in method match of re.Pattern object>)[source]: Return the Python representation of s (a str instance containing a JSON document).

raw_decode(s, idx=0)[source]

Decode a JSON document from s (a str beginning with a JSON document) and return a 2-tuple of the Python representation and the index in s where the document ended.

This can be used to decode a JSON document from a string that may have extraneous data at the end.

class smarter.lib.json.SmarterJSONEncoder(*, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, sort_keys=False, indent=None, separators=None, default=None)[source]

Bases: JSONEncoder

JSONEncoder subclass that knows how to encode odd types like

date/time
decimal
UUIDs
TaggableManager

default(o)[source]

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)
    # Let the base class default method raise the TypeError
    return super().default(o)

smarter.lib.json.dumps(obj, *, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, cls=None, indent=None, separators=None, default=None, sort_keys=False, **kw)[source]: JSON dump with - SmarterJSONEncoder as default encoder - indent of 2 - default of str

smarter.lib.json.load(fp, *, cls=None, object_hook=None, parse_float=None, parse_int=None, parse_constant=None, object_pairs_hook=None, **kw)[source]

Deserialize fp (a .read()-supporting file-like object containing a JSON document) to a Python object.

object_hook is an optional function that will be called with the result of any object literal decode (a dict). The return value of object_hook will be used instead of the dict. This feature can be used to implement custom decoders (e.g. JSON-RPC class hinting).

object_pairs_hook is an optional function that will be called with the result of any object literal decoded with an ordered list of pairs. The return value of object_pairs_hook will be used instead of the dict. This feature can be used to implement custom decoders. If object_hook is also defined, the object_pairs_hook takes priority.

To use a custom JSONDecoder subclass, specify it with the cls kwarg; otherwise JSONDecoder is used.

smarter.lib.json.loads(s, *, cls=None, object_hook=None, parse_float=None, parse_int=None, parse_constant=None, object_pairs_hook=None, **kw)[source]

Deserialize s (a str, bytes or bytearray instance containing a JSON document) to a Python object.