update rot13.py (#1790)

* update rot13.py

* Update rot13.py

* Type hints, doctests, URL to Wikipedia

Co-authored-by: Christian Clauss <cclauss@me.com>
This commit is contained in:
Aakash Dinkar 2020-03-08 11:34:21 +05:30 committed by GitHub
parent a9f73e318c
commit 182e3042f8
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23

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@ -1,9 +1,19 @@
def dencrypt(s, n):
def dencrypt(s: str, n: int=13):
"""
https://en.wikipedia.org/wiki/ROT13
>>> msg = "My secret bank account number is 173-52946 so don't tell anyone!!"
>>> s = dencrypt(msg)
>>> s
"Zl frperg onax nppbhag ahzore vf 173-52946 fb qba'g gryy nalbar!!"
>>> dencrypt(s) == msg
True
"""
out = ""
for c in s:
if c >= "A" and c <= "Z":
if "A" <= c <= "Z":
out += chr(ord("A") + (ord(c) - ord("A") + n) % 26)
elif c >= "a" and c <= "z":
elif "a" <= c <= "z":
out += chr(ord("a") + (ord(c) - ord("a") + n) % 26)
else:
out += c
@ -11,14 +21,16 @@ def dencrypt(s, n):
def main():
s0 = "HELLO"
s0 = input("Enter message: ")
s1 = dencrypt(s0, 13)
print(s1) # URYYB
print("Encryption:", s1)
s2 = dencrypt(s1, 13)
print(s2) # HELLO
print("Decryption: ", s2)
if __name__ == "__main__":
import doctest
doctest.testmod()
main()