rot13のプログラム

rot13.py

# Reference:
# https://blog.finxter.com/how-to-use-rot13-in-python/
import argparse

ap = argparse.ArgumentParser()
ap.add_argument('arg1', help='plain text')
ap.add_argument('-n', help='number of rotation')
args = ap.parse_args()

cleartxt = args.arg1
abc = "abcdefghijklmnopqrstuvwxyz"
if args.n is None:
    rot_n = 13
else:
    rot_n = int(args.n)
secret = "".join([abc[(abc.find(c)+rot_n)%26] for c in cleartxt])
print(secret)