def decrypt(message): """ >>> decrypt('TMDETUX PMDVU') Decryption using Key #0: TMDETUX PMDVU Decryption using Key #1: SLCDSTW OLCUT Decryption using Key #2: RKBCRSV NKBTS Decryption using Key #3: QJABQRU MJASR Decryption using Key #4: PIZAPQT LIZRQ Decryption using Key #5: OHYZOPS KHYQP Decryption using Key #6: NGXYNOR JGXPO Decryption using Key #7: MFWXMNQ IFWON Decryption using Key #8: LEVWLMP HEVNM Decryption using Key #9: KDUVKLO GDUML Decryption using Key #10: JCTUJKN FCTLK Decryption using Key #11: IBSTIJM EBSKJ Decryption using Key #12: HARSHIL DARJI Decryption using Key #13: GZQRGHK CZQIH Decryption using Key #14: FYPQFGJ BYPHG Decryption using Key #15: EXOPEFI AXOGF Decryption using Key #16: DWNODEH ZWNFE Decryption using Key #17: CVMNCDG YVMED Decryption using Key #18: BULMBCF XULDC Decryption using Key #19: ATKLABE WTKCB Decryption using Key #20: ZSJKZAD VSJBA Decryption using Key #21: YRIJYZC URIAZ Decryption using Key #22: XQHIXYB TQHZY Decryption using Key #23: WPGHWXA SPGYX Decryption using Key #24: VOFGVWZ ROFXW Decryption using Key #25: UNEFUVY QNEWV """ LETTERS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" for key in range(len(LETTERS)): translated = "" for symbol in message: if symbol in LETTERS: num = LETTERS.find(symbol) num = num - key if num < 0: num = num + len(LETTERS) translated = translated + LETTERS[num] else: translated = translated + symbol print("Decryption using Key #%s: %s" % (key, translated)) def main(): message = input("Encrypted message: ") message = message.upper() decrypt(message) if __name__ == '__main__': import doctest doctest.testmod() main()