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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 short_key():
 """ Generate a short key. 5 """

    firstlast = list(ascii_letters + digits)
    middle = firstlast + list('-_')
    return ''.join((
        choice(firstlast), choice(middle), choice(middle),
        choice(middle), choice(firstlast),
    ))