import argparse parser = argparse.ArgumentParser() parser.add_argument("-i", metavar="in-file", type=argparse.FileType("rt")) parser.add_argument("-o", metavar="out-file", type=argparse.FileType("wt")) try: results = parser.parse_args() print("input file: ", results.i) print("output file: ", results.o) except IOError as msg: parser.error(str(msg)) # python argparse_FileType.py -h # python argparse_FileType.py -i argparse_FileType.py # python argparse_FileType.py -i argparse_FileType.py -o /tmp/file.txt # python argparse_FileType.py -i nosuchfile.txt