python null变成nan,Python JSON编码器将NaN改为'null'

I'm writing code to receive an arbitrary object (possibly nested) capable of being converted to JSON.

The default behavior for Python's builtin JSON encoder is to convert NaNs to NaN, e.g. json.dumps(np.NaN) results in NaN. How can I change this NaN value to 'null'?

from json import JSONEncoder, dumps

import numpy as np

class NanConverter(JSONEncoder):

def default(self, obj):

try:

_ = iter(obj)

except TypeError:

if isinstance(obj, float) and np.isnan(obj):

return "null"

return JSONEncoder.default(self, obj)

>>> d = {'a': 1, 'b': 2, 'c': 3, 'e': np.nan, 'f': [1, np.nan, 3]}

>>> dumps(d, cls=NanConverter)

'{"a": 1, "c": 3, "b": 2, "e": NaN, "f": [1, NaN, 3]}'

EXPECTED RESULT: '{"a": 1, "c": 3, "b": 2, "e": null, "f": [1, null, 3]}'

解决方案

This seems to achieve my objective:

import simplejson

>>> simplejson.dumps(d, ignore_nan=True)

Out[3]: '{"a": 1, "c": 3, "b": 2, "e": null, "f": [1, null, 3]}'