Django Rest Framework Json data monkey patching

Question

I ran into a problem with a floating point number like 3.333333333 , and I want to make it 3.33 . I do not want to change the entire Serializer class where this value type comes from. There are thousands of serializers, and they have several fields that matter, such as 3.333333333 .

Could you help me find a solution like monkey patch so that I write a single class or function to convert only float values.

Answer 1

I worked on some code. I made changes to the following files

settings.py

 REST_FRAMEWORK = { 'DEFAULT_RENDERER_CLASSES': ( 'utils.renderers.PalJSONRenderer', 'rest_framework.renderers.BrowsableAPIRenderer', )} 

utils / renderers.py

  from rest_framework.renderers import JSONRenderer from rest_framework.utils.encoders import JSONEncoder from json.encoder import encode_basestring_ascii, encode_basestring, INFINITY, _make_iterencode class CustomJSONEncoder(JSONEncoder): def iterencode(self, o, _one_shot=False): """Encode the given object and yield each string representation as available. For example:: for chunk in JSONEncoder().iterencode(bigobject): mysocket.write(chunk) """ # Hack to enforce c_make_encoder = None if self.check_circular: markers = {} else: markers = None if self.ensure_ascii: _encoder = encode_basestring_ascii else: _encoder = encode_basestring def floatstr(o, allow_nan=self.allow_nan, _repr=lambda o: format(o, '.2f'), _inf=INFINITY, _neginf=-INFINITY): # Check for specials. Note that this type of test is processor # and/or platform-specific, so do tests which don't depend on the # internals. if o != o: text = 'NaN' elif o == _inf: text = 'Infinity' elif o == _neginf: text = '-Infinity' else: return _repr(o) if not allow_nan: raise ValueError( "Out of range float values are not JSON compliant: " + repr(o)) return text if (_one_shot and c_make_encoder is not None and self.indent is None): _iterencode = c_make_encoder( markers, self.default, _encoder, self.indent, self.key_separator, self.item_separator, self.sort_keys, self.skipkeys, self.allow_nan) else: _iterencode = _make_iterencode( markers, self.default, _encoder, self.indent, floatstr, self.key_separator, self.item_separator, self.sort_keys, self.skipkeys, _one_shot) return _iterencode(o, 0) class PalJSONRenderer(JSONRenderer): encoder_class = CustomJSONEncoder