Swap_letters review

solutions/Swap_letters.py

@@ -0,0 +1,39 @@
+"""
+Created on 08/01/2024
+
+@author: Tibyan Khalid
+
+This file contains the function Swap_letters that swaps the case of each letter in a string.
+"""
+
+
+def Swap_letters(string: str) -> str:
+    """Swap_letters will return the string given with switched cases.
+
+    Parameters:
+      String(str) "the word that will get modified"
+
+    Returns: modified_string(str) "the string with swapped cases"
+
+    >>> Swap_letters("hello")
+    'HELLO'
+
+    >>> Swap_letters("HELLO")
+    'hello'
+
+    >>> Swap_letters("HeLlO")
+    'hElLo'
+    """
+    if not isinstance(string, str):
+        "Make sure the expected input is a string"
+        raise AssertionError("Input must be a string")
+
+    changed_string = ""
+    for char in string:
+        if char.islower():
+            changed_string += char.upper()
+        elif char.isupper():
+            changed_string += char.lower()
+        else:
+            changed_string += char
+    return changed_string

solutions/tests/test_Swap_letters.py

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+"""
+Created on 08/01/2024
+
+@author: Tibyan Khalid
+
+This file contains boundary cases and defensive assertion tests for the function Swap_letters.
+"""
+
+import unittest
+
+from ..Swap_letters import Swap_letters
+
+
+class TestSwapLettersFunctionality(unittest.TestCase):
+    """Test cases for validating the behavior of the Swap_letters function,
+    including edge cases and defensive assertions."""
+
+    def test_lowercase_all(self):
+        "Testing from lowercase to uppercase"
+        self.assertEqual(Swap_letters("tibyan"), "TIBYAN")
+
+    def test_uppercase_all(self):
+        "Testing from uppercase to lowercase"
+        self.assertEqual(Swap_letters("TIBYAN"), "tibyan")
+
+    def test_mixed_cases(self):
+        "Testing mixed spaces"
+        self.assertEqual(Swap_letters("TiByAn"), "tIbYaN")
+
+    def test_non_string_entry(self):
+        "Raise an error if entry is not a string"
+        with self.assertRaises(AssertionError):
+            Swap_letters(57)
+
+    def test_spaces(self):
+        "Handle spaces correctly"
+        self.assertEqual(Swap_letters("Hello World"), "hELLO wORLD")
+
+    def test_empty_string(self):
+        "Test for an empty string input"
+        self.assertEqual(Swap_letters(""), "")
+
+    def test_special_characters(self):
+        "Test for special characters input"
+        self.assertEqual(Swap_letters("1234!@#$"), "1234!@#$")
+
+
+if __name__ == "__main__":
+    unittest.main()