Contributes to #9943

.devcontainer/devcontainer.json

@@ -7,7 +7,7 @@
 			// Update 'VARIANT' to pick a Python version: 3, 3.11, 3.10, 3.9, 3.8
 			// Append -bullseye or -buster to pin to an OS version.
 			// Use -bullseye variants on local on arm64/Apple Silicon.
-			"VARIANT": "3.12-bookworm",
+			"VARIANT": "3.12-bookworm"
 		}
 	},
 

.gitignore

@@ -108,3 +108,4 @@ venv.bak/
 .try
 .vscode/
 .vs/
+.devcontainer/devcontainer.json

ciphers/rot13.py

@@ -1,32 +1,49 @@
-def dencrypt(s: str, n: int = 13) -> str:
+def dencrypt(s: str) -> str:
     """
+    Applies the ROT13 cipher to the input string, `s`, shifting each alphabetic character 
+    by 13 positions within the alphabet. This cipher is symmetrical, meaning applying it 
+    twice returns the original text. Non-alphabet characters are left unchanged.
+
     https://en.wikipedia.org/wiki/ROT13
 
+    Args:
+        s (str): The input string to be encoded/decoded using ROT13.
+
+    Returns:
+        str: The encoded/decoded string after applying the ROT13 transformation.
+
+    Raises:
+        TypeError: If the input `s` is not a string.
+
     >>> 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 = ""
+    if not isinstance(s, str):
+        raise TypeError("Input must be a string.")
+
+    out = []
     for c in s:
         if "A" <= c <= "Z":
-            out += chr(ord("A") + (ord(c) - ord("A") + n) % 26)
+            out.append(chr(ord("A") + (ord(c) - ord("A") + 13) % 26))
         elif "a" <= c <= "z":
-            out += chr(ord("a") + (ord(c) - ord("a") + n) % 26)
+            out.append(chr(ord("a") + (ord(c) - ord("a") + 13) % 26))
         else:
-            out += c
-    return out
+            out.append(c)
+    return ''.join(out)
 
 
 def main() -> None:
     s0 = input("Enter message: ")
 
-    s1 = dencrypt(s0, 13)
+    s1 = dencrypt(s0)
     print("Encryption:", s1)
 
-    s2 = dencrypt(s1, 13)
+    s2 = dencrypt(s1)
     print("Decryption: ", s2)
 
 

strings/indian_phone_validator.py

@@ -26,4 +26,22 @@ def indian_phone_validator(phone: str) -> bool:
 
 
 if __name__ == "__main__":
+    """
+    Main entry point of the script.
+
+    This block checks if the script is being run as the main module. If so, it calls
+    the `indian_phone_validator` function with a sample phone number and
+    prints the result.
+
+    Functions:
+        indian_phone_validator(phone: str) -> bool:
+            Validates if the given phone number is a valid Indian phone number.
+            The function is expected to return `True` if the number is valid,
+            otherwise `False`.
+
+    Example:
+        $ python indian_phone_validator.py
+        True  # (if the phone number "+918827897895" is valid)
+    Note: Ensure that the `indian_phone_validator()` function is defined.
+    """
     print(indian_phone_validator("+918827897895"))