def patch()

in app/app.py [0:0]

• 17 lines of code
• 4 McCabe index (conditional complexity)

    def patch(cls, event: EventType) -> Tuple[int, Dict[str, str]]:
        user_id = event['pathParameters']['user_id']
        parameters = json.loads(event['body'])

        try:
            response = table.update_item(
                Key={'user_id': user_id},

                # Assign an alias to a reserved word.
                UpdateExpression='SET #nm = :newname',
                ExpressionAttributeNames={'#nm': 'name'},

                # Condition to avoid creating new item if a datum that has specified id is already stored
                ConditionExpression='user_id = :user_id',

                ExpressionAttributeValues={':newname': parameters['name'], ':user_id': user_id},
                ReturnValues='UPDATED_NEW',
            )
        except ClientError as e:
            if e.response['Error']['Code'] == 'ConditionalCheckFailedException':
                return 404, {'message': 'No such user found'}
            raise

        return 200, {'user_id': user_id, 'name': response['Attributes']['name']}