[pull] master from geekcomputers:master

secret_language.py

@@ -0,0 +1,86 @@
+# Encoding & Decoding
+
+import random
+import string
+
+
+def random_chars() -> str:
+    """
+    Generate a random string of 3 ASCII letters.
+
+    >>> import random
+    >>> random.seed(42)
+    >>> random_chars()
+    'ZoX'
+    """
+    return ''.join(random.choices(string.ascii_letters, k=3))
+
+
+def random_digits() -> str:
+    """
+    Generate a random string of 3 digits.
+
+    >>> import random
+    >>> random.seed(42)
+    >>> random_digits()
+    '638'
+    """
+    return ''.join(random.choices(string.digits, k=3))
+
+
+def encode(code: str) -> str:
+    """
+    Encode a string by shifting the first character to the end and
+    wrapping it with random padding of 3 letters and 3 digits on each side.
+
+    Reference: https://en.wikipedia.org/wiki/Caesar_cipher
+
+    >>> import random
+    >>> random.seed(42)
+    >>> encode('hello')
+    'ZoX638elloh415mJu'
+
+    >>> import random
+    >>> random.seed(42)
+    >>> encode('hi')
+    'ZoX638ih415mJu'
+    """
+    if len(code) >= 3:
+        code = code[1:] + code[0]
+        code = random_chars() + random_digits() + code + random_digits() + random_chars()
+    else:
+        code = code[::-1]
+        code = random_chars() + random_digits() + code + random_digits() + random_chars()
+    return code
+
+
+def decode(code: str) -> str:
+    """
+    Decode an encoded string by stripping the random padding and
+    reversing the character shift.
+
+    >>> import random
+    >>> random.seed(42)
+    >>> decode(encode('hello'))
+    'hello'
+
+    >>> import random
+    >>> random.seed(42)
+    >>> decode(encode('hi'))
+    'hi'
+    """
+    code = code[6:-6]
+    if len(code) >= 3:
+        code = code[-1] + code[:-1]
+    else:
+        code = code[::-1]
+    return code
+
+
+if __name__ == "__main__":
+    code = input("Enter the code: ")
+    encoded = encode(code)
+    decoded = decode(encoded)
+    print(f"Original → {code}")
+    print(f"Encoded  → {encoded}")
+    print(f"Decoded  → {decoded}")