def group_episodes_by_writer(episodes):
    """Utilizes a dictionary to group individual episodes by a contributing writer. The writer's
    name comprises the key and the associated value comprises a list of one or more episode
    dictionaries. Duplicate keys are NOT permitted.

    Format:
        {
            < writer name >: [{< episode_01 >}, {< episode_02 >}, ...],
            < writer name >: [{< episode_01 >}, {< episode_02 >}, ...],
            ...
        }

    Parameters:
        episodes (list): nested episode dictionaries

    Returns:
        dict: a dictionary that groups episodes by a contributing writer
    """
    result = {}
    for ep in range(len(episodes)):
        print(episodes[ep]['episode_writers'])
        for write in episodes[ep]['episode_writers']:
            if write in result:
                result[write] += [(episodes[ep])]
            else:
                result[write] = [(episodes[ep])]

    return result