how to json serialize objects in python [duplicate]

Question

Does python support random json serialization? I get this error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "commands.py", line 36, in toJson
    return json.dumps(self)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/__init__.py", line 231, in dumps
    return _default_encoder.encode(obj)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/encoder.py", line 201, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/encoder.py", line 264, in iterencode
    return _iterencode(o, 0)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/encoder.py", line 178, in default
    raise TypeError(repr(o) + " is not JSON serializable")
TypeError: <commands.SampleCommand object at 0x105d957d0> is not JSON serializable

Snippet:

class SampleCommand(Command):
    def __init__(self,message=None):
        super(Command, self).__init__()
        pass

    def parse(self):
        pass

    def toJson(self):
        return json.dumps(self)

stackoverflow.com/questions/1458450/… and stackoverflow.com/questions/3768895/…. — user545424
– user545424, Commented Jun 24, 2012 at 2:53

Samy Vilar · Accepted Answer · 2012-06-24 02:54:37Z

10

json within python by default can only handle certain objects like dictionaries, list and basic types such as ints, strings and so on for more complex types you need to define your own serialization scheme

>>> help(json)
Extending JSONEncoder::

    >>> import json
    >>> class ComplexEncoder(json.JSONEncoder):
    ...     def default(self, obj):
    ...         if isinstance(obj, complex):
    ...             return [obj.real, obj.imag]
    ...         return json.JSONEncoder.default(self, obj)
    ...
    >>> dumps(2 + 1j, cls=ComplexEncoder)
    '[2.0, 1.0]'
    >>> ComplexEncoder().encode(2 + 1j)
    '[2.0, 1.0]'
    >>> list(ComplexEncoder().iterencode(2 + 1j))
    ['[', '2.0', ', ', '1.0', ']']

answered Jun 24, 2012 at 2:54

Samy Vilar

11.2k2 gold badges42 silver badges34 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Felix Over a year ago

You should point explicitly that your code is an example of extending the JSONEncoder to add the ability to serialize python "complex numbers" into JSON.

Samy Vilar Over a year ago

@FelixBonkoski note the >>> help(json) this is nothing more then taken right from the docs, I was trying to emphasize that if you are interesting/stuck in a python module the first step is to call help

Collectives™ on Stack Overflow

how to json serialize objects in python [duplicate]

1 Answer 1

2 Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Linked

Related