2

mat/mat.py

+def sub(M, m, n, x, y):
+    import numpy as np
+    M=np.array(M)
+    print (M[x:x+m , y:y+n])
+M = [
+[3, 2, 1, 2],
+[5, 4, 3, 3],
+[7, 3, 6, 4]
+]

mat/tests/test_example.py

+"""
+Example test.
+
+"""
+from hamcrest import (
+    assert_that,
+    equal_to,
+    is_,
+)
+
+
+def test_math():
+    assert_that(1 + 1, is_(equal_to(2)))