Fix special character handling and update test cases based on review

solutions/is_palindrome.py

@@ -31,12 +31,23 @@ def is_palindrome(text: str) -> bool:
         False
         >>> is_palindrome("A man a plan a canal Panama")
         True
+        >>> is_palindrome("$+$")
+        True
+        >>> is_palindrome("$+#")
+        False
     """
     # Ensure the input is of type string to avoid unexpected errors.
     assert isinstance(text, str), "Input must be a string"
 
     # Normalize the text: remove spaces and convert to lowercase
-    normalized = "".join(char.lower() for char in text if char.isalnum())
+    normalized = "".join([char.lower() for char in text if not char.isspace()])
 
     # Check if the string is the same when reversed
     return normalized == normalized[::-1]
+
+
+if __name__ == "__main__":
+    # Example cases to test functionality
+    print(is_palindrome("$+$"))  # Should return True
+    print(is_palindrome("$+#"))  # Should return False
+    print(is_palindrome("A man a plan a canal Panama"))  # Should return True

solutions/tests/test_is_palindrome.py

@@ -1,3 +1,22 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Unit tests for the is_palindrome function.
+
+This module contains test cases for the is_palindrome function,
+which checks if a string is a palindrome. The tests cover:
+
+- Empty strings
+- Single-character strings
+- Palindromes with lowercase, mixed-case, and spaces
+- Palindromes containing numbers
+- Palindromes containing special characters
+- Non-palindromes
+
+Created on 2024-12-30
+Author: Emre Biyik
+"""
+
 import unittest
 from solutions.is_palindrome import is_palindrome
 
@@ -53,6 +72,14 @@ def test_non_palindrome_with_special_characters_returns_false(self):
         """It should return False for non-palindromes with special characters."""
         self.assertFalse(is_palindrome("hello!"))
 
+    def test_special_characters_palindrome_positive(self):
+        """It should return True for special character palindrome."""
+        self.assertTrue(is_palindrome("$+$"))  # Palindrome
+
+    def test_special_characters_palindrome_negative(self):
+        """It should return False for non-palindrome special characters."""
+        self.assertFalse(is_palindrome("$+#"))  # Non-palindrome
+
 
 if __name__ == "__main__":
     unittest.main()