python(test): enable pylint checks for tests

modules/python/test/test_calibration.py

@@ -16,8 +16,6 @@ from tests_common import NewOpenCVTests
 class calibration_test(NewOpenCVTests):
 
     def test_calibration(self):
-
-        from glob import glob
         img_names = []
         for i in range(1, 15):
             if i < 10:
@@ -34,7 +32,6 @@ class calibration_test(NewOpenCVTests):
         obj_points = []
         img_points = []
         h, w = 0, 0
-        img_names_undistort = []
         for fn in img_names:
             img = self.get_sample(fn, 0)
             if img is None:
@@ -53,7 +50,7 @@ class calibration_test(NewOpenCVTests):
             obj_points.append(pattern_points)
 
         # calculate camera distortion
-        rms, camera_matrix, dist_coefs, rvecs, tvecs = cv2.calibrateCamera(obj_points, img_points, (w, h), None, None, flags = 0)
+        rms, camera_matrix, dist_coefs, _rvecs, _tvecs = cv2.calibrateCamera(obj_points, img_points, (w, h), None, None, flags = 0)
 
         eps = 0.01
         normCamEps = 10.0