Added stack min challenge.

stacks_queues/stack_min/test_stack_min.py

@@ -0,0 +1,41 @@
+from nose.tools import assert_equal
+
+
+class TestStackMin(object):
+    def test_stack_min(self):
+        print('Test: Push on empty stack, non-empty stack')
+        stack = MyStack()
+        stack.push(5)
+        assert_equal(stack.peek(), 5)
+        assert_equal(stack.min(), 5)
+        stack.push(1)
+        assert_equal(stack.peek(), 1)
+        assert_equal(stack.min(), 1)
+        stack.push(3)
+        assert_equal(stack.peek(), 3)
+        assert_equal(stack.min(), 1)
+        stack.push(0)
+        assert_equal(stack.peek(), 0)
+        assert_equal(stack.min(), 0)
+
+        print('Test: Pop on non-empty stack')
+        assert_equal(stack.pop(), 0)
+        assert_equal(stack.min(), 1)
+        assert_equal(stack.pop(), 3)
+        assert_equal(stack.min(), 1)
+        assert_equal(stack.pop(), 1)
+        assert_equal(stack.min(), 5)
+        assert_equal(stack.pop(), 5)
+        assert_equal(stack.min(), sys.maxint)
+
+        print('Test: Pop empty stack')
+        assert_equal(stack.pop(), None)
+        
+        print('Success: test_stack_min')
+
+def main():
+    test = TestStackMin()
+    test.test_stack_min()
+
+if __name__ == '__main__':
+    main()