MAINT: cleanup unused imports; avoid redefinition of imports

* Cleanup unused imports (F401) of mostly standard Python modules,
  or some internal but unlikely referenced modules
* Where internal imports are potentially used, mark with noqa
* Avoid redefinition of imports (F811)

3 files changed, 1 insertions, 4 deletions

diff --git a/numpy/tests/test_reloading.py b/numpy/tests/test_reloading.py
index a6d2e62a9..860832be8 100644
--- a/numpy/tests/test_reloading.py
+++ b/numpy/tests/test_reloading.py
@@ -1,5 +1,3 @@
-import sys
-
 from numpy.testing import assert_raises, assert_, assert_equal
 from numpy.compat import pickle
 
diff --git a/numpy/tests/test_scripts.py b/numpy/tests/test_scripts.py
index 658606f82..a0f2ba70a 100644
--- a/numpy/tests/test_scripts.py
+++ b/numpy/tests/test_scripts.py
@@ -9,7 +9,7 @@ from os.path import join as pathjoin, isfile, dirname
 import subprocess
 
 import numpy as np
-from numpy.testing import assert_, assert_equal
+from numpy.testing import assert_equal
 
 is_inplace = isfile(pathjoin(dirname(np.__file__),  '..', 'setup.py'))
 
diff --git a/numpy/tests/test_warnings.py b/numpy/tests/test_warnings.py
index c4c206542..d7a6d880c 100644
--- a/numpy/tests/test_warnings.py
+++ b/numpy/tests/test_warnings.py
@@ -2,7 +2,6 @@
 Tests which scan for certain occurrences in the code, they may not find
 all of these occurrences but should catch almost all.
 """
-import sys
 import pytest
 
 from pathlib import Path