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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 pretty_bytes(num):
 """ pretty print the given number of bytes """

    for unit in ['', 'KB', 'MB', 'GB']:
        if num < 1024.0:
            if unit == '':
                return "%d" % (num)
            else:
                return "%3.1f%s" % (num, unit)
        num /= 1024.0
    return "%3.1f%s" % (num, 'TB')