Python: hamming is added

python/hamming/hamming_test.py

@@ -0,0 +1,46 @@
+import unittest
+
+from hamming import distance
+
+# Tests adapted from `problem-specifications//canonical-data.json`
+
+
+class HammingTest(unittest.TestCase):
+    def test_empty_strands(self):
+        self.assertEqual(distance("", ""), 0)
+
+    def test_single_letter_identical_strands(self):
+        self.assertEqual(distance("A", "A"), 0)
+
+    def test_single_letter_different_strands(self):
+        self.assertEqual(distance("G", "T"), 1)
+
+    def test_long_identical_strands(self):
+        self.assertEqual(distance("GGACTGAAATCTG", "GGACTGAAATCTG"), 0)
+
+    def test_long_different_strands(self):
+        self.assertEqual(distance("GGACGGATTCTG", "AGGACGGATTCT"), 9)
+
+    def test_disallow_first_strand_longer(self):
+        with self.assertRaisesWithMessage(ValueError):
+            distance("AATG", "AAA")
+
+    def test_disallow_second_strand_longer(self):
+        with self.assertRaisesWithMessage(ValueError):
+            distance("ATA", "AGTG")
+
+    def test_disallow_left_empty_strand(self):
+        with self.assertRaisesWithMessage(ValueError):
+            distance("", "G")
+
+    def test_disallow_right_empty_strand(self):
+        with self.assertRaisesWithMessage(ValueError):
+            distance("G", "")
+
+    # Utility functions
+    def assertRaisesWithMessage(self, exception):
+        return self.assertRaisesRegex(exception, r".+")
+
+
+if __name__ == "__main__":
+    unittest.main()