custom exception ahndler for django rest-framework

cudstom_exception_handler.py

from rest_framework.views import exception_handler
from rest_framework.exceptions import ErrorDetail


def custom_exception_handler(exc, context):
    if hasattr(exc, 'detail'):
        if isinstance(exc.detail, ErrorDetail):
            context['kwargs']['message'] = exc.detail.title()
        else:
            t = exc.get_full_details().popitem()
            context['kwargs']['message'] = "input parameters are not valid."
            context['kwargs']['exception'] = "{}: {}".format(t[0], t[1][0]['message'].title())
        context['kwargs']['code'] = exc.status_code
    response = exception_handler(exc, context)
    if hasattr(response, 'data'):
        response.data = {}
    return response

custom_renderer.py

from __future__ import unicode_literals

from django.utils import six
from rest_framework.compat import (
    INDENT_SEPARATORS, LONG_SEPARATORS, SHORT_SEPARATORS
)
from rest_framework.renderers import JSONRenderer
from rest_framework.utils import json


def zero_as_none(value):
    return None if value == 0 else value


class CustomRenderer(JSONRenderer):
    def render(self, data, accepted_media_type=None, renderer_context=None):
        if data is None:
            return bytes()

        renderer_context = renderer_context or {}
        indent = self.get_indent(accepted_media_type, renderer_context)
        new_data = {
            'code': None,
            'message': '',
            'exception': '',
            'data': {},
        }
        if indent is None:
            separators = SHORT_SEPARATORS if self.compact else LONG_SEPARATORS
        else:
            separators = INDENT_SEPARATORS

        if 'code' in renderer_context['kwargs'].keys():
            new_data['code'] = renderer_context['kwargs']['code']
        else:
            new_data['code'] = renderer_context['response'].status_code

        if 'message' in renderer_context['kwargs'].keys():
            new_data['message'] = renderer_context['kwargs']['message']

        if 'exception' in renderer_context['kwargs'].keys():
            new_data['exception'] = renderer_context['kwargs']['exception']

        new_data['data'] = data
        ret = json.dumps(
            new_data, cls=self.encoder_class,
            indent=indent, ensure_ascii=self.ensure_ascii,
            allow_nan=not self.strict, separators=separators
        )

        if isinstance(ret, six.text_type):
            ret = ret.replace('\u2028', '\\u2028').replace('\u2029', '\\u2029')
            return bytes(ret.encode('utf-8'))
        return ret

to design a good api we should consider many things.
imagine we should call a web service in our api and we should response it.
there are some conditions that should be covered in expose.
if our api works correctly but the web service has not and upside down.
this file can handle all the exception type that we should expose.

we can access the kwargs from view by this function self.get_renderer_context() and set kwargs like message, code and exception .

and this custom renderer can handle the expose