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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 format_survival_rate():
 """cr-rate Usage: cr-rate <session-file> Calculate the survival rate of a session. """

    arguments = docopt.docopt(
        format_survival_rate.__doc__, version='cr-rate 1.0')
    with use_db(arguments['<session-file>'], WorkDB.Mode.open) as db:
        rate = survival_rate(db)

    print('{:.2f}'.format(rate))