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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 snapshot_peek_number( fd, off ):
 """ Read the last 8 bytes of fd and interpret it as an int. """

    # read number of 8 bytes 
    fd.seek( off - 8, os.SEEK_SET )
    value_hex = fd.read(8)
    if len(value_hex) != 8:
        return None
    try:
        value = int(value_hex, 16)
    except ValueError:
        return None

    return value