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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 pp_timestamp(t):
 """ Get a friendly timestamp represented as a string. """

    if t is None:
        return ''
    h, m, s = int(t / 3600), int(t / 60 % 60), t % 60
    return "%02d:%02d:%05.2f" % (h, m, s)