Fix pylint warnings

Author: deshipu

tests/test_bitmap_c_interface.py

@@ -65,11 +65,8 @@ def test_non_zero(self):
 
     def test_throws_x_out_of_range(self):
         b = Bitmap_C_Interface(2, 4, 1)
-        try:
+        with self.assertRaises(ValueError):
             b[2, 1] = 100
-            self.fail("should have thrown")
-        except ValueError:
-            pass
 
     def test_max(self):
         b = Bitmap_C_Interface(2, 4, 1)
@@ -78,18 +75,13 @@ def test_max(self):
 
     def test_uninitialized(self):
         b = Bitmap_C_Interface(2, 4, 1)
-        try:
+        with self.assertRaises(RuntimeError):
             b[1, 1]
-            self.fail("should have thrown")
-        except RuntimeError:
-            pass
 
-    def test_validate_throws(self):
+    def test_validate_throws():
         b = Bitmap_C_Interface(2, 4, 1)
-        try:
+        with self.assertRaises(ValueError):
             b.validate()
-        except ValueError:
-            pass
 
     def test_repr(self):
         b = Bitmap_C_Interface(3, 2, 1)