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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 to_existing_absolute_path(string):
 """Converts a path into its absolute path and verifies that it exists or throws an exception."""

    value = os.path.abspath(string)
    if not os.path.exists( value ) or not os.path.isdir( value ):
        msg = '"%r" is not a valid path to a directory.' % string
        raise argparse.ArgumentTypeError(msg)
    return value