2 files changed, 20 insertions, 5 deletions
diff --git a/Lib/test/pickletester.py b/Lib/test/pickletester.py
index 7c8383f3ea..9401043d78 100644
--- a/Lib/test/pickletester.py
+++ b/Lib/test/pickletester.py
@@ -21,19 +21,25 @@ try:
 except ImportError:
     _testbuffer = None
 
-try:
-    import numpy as np
-except ImportError:
-    np = None
-
 from test import support
 from test.support import (
     TestFailed, TESTFN, run_with_locale, no_tracing,
     _2G, _4G, bigmemtest, reap_threads, forget,
+    save_restore_warnings_filters
     )
 
 from pickle import bytes_types
 
+
+# bpo-41003: Save/restore warnings filters to leave them unchanged.
+# Ignore filters installed by numpy.
+try:
+    with save_restore_warnings_filters():
+        import numpy as np
+except ImportError:
+    np = None
+
+
 requires_32b = unittest.skipUnless(sys.maxsize < 2**32,
                                    "test is only meaningful on 32-bit builds")
 
diff --git a/Lib/test/support/__init__.py b/Lib/test/support/__init__.py
index 08d53ec706..0906e7adba 100644
--- a/Lib/test/support/__init__.py
+++ b/Lib/test/support/__init__.py
@@ -3368,3 +3368,12 @@ class catch_threading_exception:
         del self.exc_value
         del self.exc_traceback
         del self.thread
+
+
+@contextlib.contextmanager
+def save_restore_warnings_filters():
+    old_filters = warnings.filters[:]
+    try:
+        yield
+    finally:
+        warnings.filters[:] = old_filters