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2faf238491
Using List for Accumulation: Instead of string concatenation within the loop, result.append() is used to create a list, and join is called at the end to concatenate the list into a string. This is more efficient for larger strings. Removed Unnecessary Parameter n: Eliminating the n parameter makes the function simpler and ensures consistent ROT13 encryption/decryption. Refactored Doctest and Assertions: The doctest examples are consistent with the revised function, ensuring reversibility through dencrypt(dencrypt(s)) == s without additional parameters.
37 lines
930 B
Python
37 lines
930 B
Python
def dencrypt(s: str) -> str:
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"""
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Applies ROT13 encryption or decryption to the input string.
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Example usage:
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>>> msg = "My secret bank account number is 173-52946 so don't tell anyone!!"
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>>> encrypted = dencrypt(msg)
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>>> encrypted
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"Zl frperg onax nppbhag ahzore vf 173-52946 fb qba'g gryy nalbar!!"
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>>> dencrypt(encrypted) == msg
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True
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"""
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result = []
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for c in s:
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if "A" <= c <= "Z":
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result.append(chr(ord("A") + (ord(c) - ord("A") + 13) % 26))
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elif "a" <= c <= "z":
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result.append(chr(ord("a") + (ord(c) - ord("a") + 13) % 26))
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else:
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result.append(c)
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return "".join(result)
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def main() -> None:
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s0 = input("Enter message: ")
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s1 = dencrypt(s0)
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print("Encryption:", s1)
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s2 = dencrypt(s1)
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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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