Fix JSONDecodeError reference

[pief]

The "requests" module does not know about JSONDecodeError because it actually comes from the underlying simplejson module. Reuse requests' internal reference so we notice if requests should ever change from simplejson to a different module.

[david-caro]

Why should we ever want to care what's the specific implementation inside requests?

[pief]

Because we need to be prepared to catch the exception and need to do so in a proper way.

Background: in PR66 I copied existing code ("except requests.JSONDecodeError"). This failed because requests does not define that error:

2016-03-01 11:21:47 GlobalExceptionHandl():630 CRITICAL:   File "/usr/lib/python2.7/site-packages/foreman/client.py", line 911, in do_get
2016-03-01 11:21:47 GlobalExceptionHandl():630 CRITICAL:     return self._process_request_result(res)
2016-03-01 11:21:47 GlobalExceptionHandl():630 CRITICAL:   File "/usr/lib/python2.7/site-packages/foreman/client.py", line 887, in _process_request_result
2016-03-01 11:21:47 GlobalExceptionHandl():630 CRITICAL:     except requests.JSONDecodeError:
2016-03-01 11:21:47 GlobalExceptionHandl():630 CRITICAL: AttributeError: 'module' object has no attribute 'JSONDecodeError'

[david-caro]

Then we should catch the proper exception defined by requests instead of going deep into requests implementation internal details no?

[pief]

Correct, but at least in my requests version (2.9.1) it doesn't seem to define an exception of its own:

    def json(self, **kwargs):
        """Returns the json-encoded content of a response, if any.

        :param \*\*kwargs: Optional arguments that ``json.loads`` takes.
        """

        if not self.encoding and len(self.content) > 3:
            # No encoding set. JSON RFC 4627 section 3 states we should expect
            # UTF-8, -16 or -32. Detect which one to use; If the detection or
            # decoding fails, fall back to `self.text` (using chardet to make
            # a best guess).
            encoding = guess_json_utf(self.content)
            if encoding is not None:
                try:
                    return complexjson.loads(
                        self.content.decode(encoding), **kwargs
                    )
                except UnicodeDecodeError:
                    # Wrong UTF codec detected; usually because it's not UTF-8
                    # but some other 8-bit codec.  This is an RFC violation,
                    # and the server didn't bother to tell us what codec *was*
                    # used.
                    pass
        return complexjson.loads(self.text, **kwargs)

[david-caro]

The docs say that it will rise a value error: http://docs.python-requests.org/en/master/user/quickstart/#json-response-content

Is that wrong?

[pief]

Ping.