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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def prompt_file(prompt, default=None, must_exist=True, is_dir=False, show_default=True, prompt_suffix=': ', color=None):
 """ Prompt a filename using using glob for autocompetion. If must_exist is True (default) then you can be sure that the value returned is an existing filename or directory name. If is_dir is True, this will show only the directories for the completion. """


    if must_exist:
        while True:
            r = prompt_autocomplete(prompt, path_complete(is_dir), default, show_default=show_default,
                                    prompt_suffix=prompt_suffix, color=color)
            if os.path.exists(r):
                break
            print('This path does not exist.')
    else:
        r = prompt_autocomplete(prompt, path_complete(is_dir), default, show_default=show_default,
                                prompt_suffix=prompt_suffix, color=color)

    return r