Add grid path challenge

recursion_dynamic/grid_path/test_grid_path.py

@@ -0,0 +1,39 @@
+from nose.tools import assert_equal
+
+
+class TestGridPath(object):
+
+    def test_grid_path(self):
+        grid = Grid()
+        assert_equal(grid.find_path(None), None)
+        assert_equal(grid.find_path([[]]), None)
+        max_rows = 8
+        max_cols = 4
+        matrix = [[1] * max_cols for _ in range(max_rows)]
+        matrix[1][1] = 0
+        matrix[2][2] = 0
+        matrix[3][0] = 0
+        matrix[4][2] = 0
+        matrix[5][3] = 0
+        matrix[6][1] = 0
+        matrix[6][3] = 0
+        matrix[7][1] = 0
+        result = grid.find_path(matrix)
+        expected = [(0, 0), (1, 0), (2, 0),
+                    (2, 1), (3, 1), (4, 1),
+                    (5, 1), (5, 2), (6, 2), 
+                    (7, 2), (7, 3)]
+        assert_equal(result, expected)
+        matrix[7][2] = 0
+        result = grid.find_path(matrix)
+        assert_equal(result, None)
+        print('Success: test_grid_path')
+
+
+def main():
+    test = TestGridPath()
+    test.test_grid_path()
+
+
+if __name__ == '__main__':
+    main()