def on_post()

in main.py [0:0]
75 lines of code
16 McCabe index (conditional complexity)

    def on_post(self, req, res):
        try:
            import falcon
            res.content_type = falcon.MEDIA_TEXT

            # Check if this is an API call
            context = None
            event = None
            using_webserver = False
            if req.url[-4:] != '/api':
                try:
                    envelope = req.media
                except falcon.MediaNotFoundError:
                    raise NoMessageReceivedException(
                        'No Pub/Sub message received')
                except falcon.MediaMalformedError:
                    raise InvalidMessageFormatException('Invalid Pub/Sub JSON')

                if not isinstance(envelope, dict) or 'message' not in envelope:
                    raise InvalidMessageFormatException(
                        'Invalid Pub/Sub message format')

                event = {
                    'data':
                        envelope['message']['data'],
                    'attributes':
                        envelope['message']['attributes']
                        if 'attributes' in envelope['message'] else {}
                }
                context = Context(eventId=envelope['message']['messageId'],
                                  timestamp=envelope['message']['publishTime'])
            else:
                try:
                    envelope = req.media
                except falcon.MediaNotFoundError:
                    raise NoMessageReceivedException('No request received')
                except falcon.MediaMalformedError:
                    raise InvalidMessageFormatException('Invalid Pub/Sub JSON')
                request_headers = req.headers
                if 'authorization' in request_headers:
                    del request_headers['authorization']
                event = {
                    'data':
                        base64.b64encode(json.dumps(envelope).encode('utf-8')),
                    'attributes': {
                        'headers': request_headers
                    }
                }
                context = Context(
                    timestamp=datetime.now().strftime('%Y-%m-%dT%H:%M:%SZ'))
                using_webserver = True

            process_pubsub(event,
                           context,
                           message_too_old_exception=True,
                           using_webserver=using_webserver)
            if context.http_response:
                res.status = context.http_response[0]
                res.set_headers(context.http_response[1])
                res.text = context.http_response[2]
            else:
                res.status = falcon.HTTP_200
                res.text = 'Message processed.'
        except (NoMessageReceivedException,
                InvalidMessageFormatException) as me:
            # Do not attempt to retry malformed messages
            logger.error('%s' % (me),
                         extra={'exception': traceback.format_exc()})
            res.status = falcon.HTTP_204
            res.text = 'Bad Request: %s' % (str(me))
        except MessageTooOldException as mtoe:
            res.status = falcon.HTTP_202
            res.text = 'Message ignored: %s' % (mtoe)
        except ImportError:
            logger.error(
                'Falcon is required for web server mode, run: pip install falcon'
            )
        except Exception as e:
            traceback.print_exc()
            res.status = falcon.HTTP_500
            res.text = 'Internal Server Error: %s' % (e)