mirror of
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60895366c0
* fix(mypy): type annotations for cipher algorithms * Update mypy workflow to include cipher directory * fix: mypy errors in hill_cipher.py * fix build errors
38 lines
841 B
Python
38 lines
841 B
Python
def dencrypt(s: str, n: int = 13) -> str:
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"""
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https://en.wikipedia.org/wiki/ROT13
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>>> msg = "My secret bank account number is 173-52946 so don't tell anyone!!"
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>>> s = dencrypt(msg)
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>>> s
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"Zl frperg onax nppbhag ahzore vf 173-52946 fb qba'g gryy nalbar!!"
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>>> dencrypt(s) == msg
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True
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"""
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out = ""
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for c in s:
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if "A" <= c <= "Z":
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out += chr(ord("A") + (ord(c) - ord("A") + n) % 26)
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elif "a" <= c <= "z":
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out += chr(ord("a") + (ord(c) - ord("a") + n) % 26)
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else:
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out += c
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return out
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def main() -> None:
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s0 = input("Enter message: ")
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s1 = dencrypt(s0, 13)
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print("Encryption:", s1)
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s2 = dencrypt(s1, 13)
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print("Decryption: ", s2)
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if __name__ == "__main__":
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import doctest
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doctest.testmod()
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main()
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