add a solution for the hamming problem

.vscode/settings.json

@@ -1,8 +1,8 @@
 {
   "python.pythonPath": "python/venv/bin/python3",
   "python.terminal.activateEnvInCurrentTerminal": true,
-  "python.testing.pytestArgs": ["python"],
   "python.testing.unittestEnabled": false,
   "python.testing.pytestEnabled": true,
-  "python.linting.enabled": true
+  "python.linting.enabled": true,
+  "python.testing.pytestArgs": ["python"]
 }

python/hamming/hamming.py

@@ -1,6 +1,11 @@
 def distance(strand_a, strand_b):
-    strand_a_length = strand_a.length()
-    strand_b_length = strand_b.length()
-   
-    print(strand_a_length)
-    pass
+    length_sum = len(strand_a) - len(strand_b)
+    if (strand_a == strand_b):
+        return 0
+    if (length_sum != 0):
+        raise ValueError("Not the same distance")
+    distance = 0
+    for i, letter in enumerate(strand_a):
+        if (letter != strand_b[i]):
+            distance += 1
+    return distance

python/hamming/hamming_test.py

@@ -1,4 +1,5 @@
 import unittest
+import pytest
 
 from hamming import (
     distance,

python/requirements.txt

@@ -0,0 +1,3 @@
+pytest
+pep8
+pylint