Unit tests for Levenshtein Edit Distance

Levenshtein_Edit_Distance.py

@@ -20,5 +20,4 @@ def edit_distance(str1, str2): #input is 2 strings that we will be comparing
         cost = 1  #no match: substitution
       D[i][j] = min(D[i-1][j] + 1, D[i][j-1] + 1,D[i-1][j-1] + cost)
 
-    return D[len(str1)][len(str2)] #last cell of matrix contains optimal solution
-
+  return D[len(str1)][len(str2)] #last cell of matrix contains optimal solution

Test_Levenshtein_Edit_Distance.py

@@ -0,0 +1,42 @@
+import unittest
+import Levenshtein_Edit_Distance
+
+class TestEditDistance(unittest.TestCase):
+    def test_empty_strings(self):
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("", ""), 0)
+
+    def test_identical_strings(self):
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("abcde", "abcde"), 0)
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("hello_world", "hello_world"), 0)
+
+    def test_different_lengths(self):
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("apple", "pineapple"), 4)
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("programming", "programmer"), 3)
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("classification", "clarification"), 2)
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("comp sci", "computer science"), 8)
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("saturday", "sunday"), 3)
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("video", "nvidia"), 3)
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("uconn", "basketball"), 10)
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("national", "champions"), 6)
+
+
+    def test_same_lengths(self):
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("intention", "execution"), 5)
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("storrs", "stores"), 1)
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("student", "faculty"), 7)
+
+    def test_one_empty_string(self):
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("computer", ""), 8)
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("", "science"), 7)
+
+    def test_different_cases(self):
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("UConn", "uconn"), 2)
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("AbC", "abc"), 2)
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("ALGORITHM", "algorithm"), 9)
+
+    def test_special_characters(self):
+        self.assertEqual(Levenshtein_Edit_Distance.edit_distance("a|b^c}", "a&b#c."), 3)
+
+if __name__ == '__main__':
+    unittest.main()
+