How to deal with 401 (unauthorised) in python requests

Question

What I want to do is GET from a site and if that request returns a 401, then redo my authentication wiggle (which may be out of date) and try again. But I don\'t want to try

Answer 1

You could have wrapped this in a function and used a decorator to evaluate the response and retry the auth on 401. Then you only need to decorate any function that requires this re-auth logic....

Update: As requested, a code example. I'm afraid this one is an old piece of code, Python 2 based, but you'll get the idea. This one will retry an http call a number of times as defined in settings.NUM_PLATFORM_RETRIES and will call a refresh_token on auth failures. you can adjust the use case and result to whatever. You can then use this decorator around methods:

@retry_on_read_error
def some_func():
   do_something()



def retry_on_read_error(fn):
    """
    Retry Feed reads on failures
    If a token refresh is required it is performed before retry.
    This decorator relies on the model to have a refresh_token method defined, othewise it will fail
    """
    @wraps(fn)
    def _wrapper(self, *args, **kwargs):
        for i in range(settings.NUM_PLATFORM_RETRIES):
            try:
                res = fn(self, *args, **kwargs)

                try:
                    _res = json.loads(res)
                except ValueError:
                    # not a json response (could be local file read or non json data)
                    return res

                if 'error' in _res and _res['error']['status'] in (401, 400):
                    raise AccessRefusedException(_res['error']['message'])

                return res
            except (urllib2.URLError, IOError, AccessRefusedException) as e:
                if isinstance(e, AccessRefusedException):
                    self.refresh_token()
                continue
        raise ApiRequestFailed(
            "Api failing, after %s retries: %s" % (settings.NUM_PLATFORM_RETRIES, e), args, kwargs
        )

    return _wrapper