Use context manager to supress certain warnings

Author: ksunden

lib/matplotlib/tests/test_backend_pdf.py

@@ -87,41 +87,42 @@ def test_multipage_keep_empty(tmp_path):
     # test empty pdf files
     # Due to order of `with` block execution, a warning for unclosed file is raised
     # but the pytest.warns must happen before the PdfPages is created
-    warnings.filterwarnings("ignore", category=ResourceWarning)
-
-    # an empty pdf is left behind with keep_empty unset
-    with pytest.warns(mpl.MatplotlibDeprecationWarning), PdfPages("a.pdf") as pdf:
-        pass
-    assert os.path.exists("a.pdf")
-
-    # an empty pdf is left behind with keep_empty=True
-    with pytest.warns(mpl.MatplotlibDeprecationWarning), \
-            PdfPages("b.pdf", keep_empty=True) as pdf:
-        pass
-    assert os.path.exists("b.pdf")
-
-    # an empty pdf deletes itself afterwards with keep_empty=False
-    with PdfPages("c.pdf", keep_empty=False) as pdf:
-        pass
-    assert not os.path.exists("c.pdf")
-
-    # test pdf files with content, they should never be deleted
-
-    # a non-empty pdf is left behind with keep_empty unset
-    with PdfPages("d.pdf") as pdf:
-        pdf.savefig(plt.figure())
-    assert os.path.exists("d.pdf")
-
-    # a non-empty pdf is left behind with keep_empty=True
-    with pytest.warns(mpl.MatplotlibDeprecationWarning), \
-            PdfPages("e.pdf", keep_empty=True) as pdf:
-        pdf.savefig(plt.figure())
-    assert os.path.exists("e.pdf")
-
-    # a non-empty pdf is left behind with keep_empty=False
-    with PdfPages("f.pdf", keep_empty=False) as pdf:
-        pdf.savefig(plt.figure())
-    assert os.path.exists("f.pdf")
+    with warnings.catch_warnings():
+        warnings.filterwarnings("ignore", category=ResourceWarning)
+
+        # an empty pdf is left behind with keep_empty unset
+        with pytest.warns(mpl.MatplotlibDeprecationWarning), PdfPages("a.pdf") as pdf:
+            pass
+        assert os.path.exists("a.pdf")
+
+        # an empty pdf is left behind with keep_empty=True
+        with pytest.warns(mpl.MatplotlibDeprecationWarning), \
+                PdfPages("b.pdf", keep_empty=True) as pdf:
+            pass
+        assert os.path.exists("b.pdf")
+
+        # an empty pdf deletes itself afterwards with keep_empty=False
+        with PdfPages("c.pdf", keep_empty=False) as pdf:
+            pass
+        assert not os.path.exists("c.pdf")
+
+        # test pdf files with content, they should never be deleted
+
+        # a non-empty pdf is left behind with keep_empty unset
+        with PdfPages("d.pdf") as pdf:
+            pdf.savefig(plt.figure())
+        assert os.path.exists("d.pdf")
+
+        # a non-empty pdf is left behind with keep_empty=True
+        with pytest.warns(mpl.MatplotlibDeprecationWarning), \
+                PdfPages("e.pdf", keep_empty=True) as pdf:
+            pdf.savefig(plt.figure())
+        assert os.path.exists("e.pdf")
+
+        # a non-empty pdf is left behind with keep_empty=False
+        with PdfPages("f.pdf", keep_empty=False) as pdf:
+            pdf.savefig(plt.figure())
+        assert os.path.exists("f.pdf")
 
 
 def test_composite_image():

lib/matplotlib/tests/test_colors.py

@@ -1,6 +1,7 @@
 import copy
 import itertools
 import unittest.mock
+import warnings
 
 from io import BytesIO
 import numpy as np
@@ -147,8 +148,11 @@ def test_double_register_builtin_cmap():
     with pytest.raises(ValueError, match='A colormap named "viridis"'):
         with pytest.warns(mpl.MatplotlibDeprecationWarning):
             cm.register_cmap(name, mpl.colormaps[name])
-    with pytest.warns(UserWarning), pytest.warns(mpl.MatplotlibDeprecationWarning):
-        cm.register_cmap(name, mpl.colormaps[name], override_builtin=True)
+
+    with warnings.catch_warnings():
+        warnings.filterwarnings("ignore", category=mpl.MatplotlibDeprecationWarning)
+        with pytest.warns(UserWarning):
+            cm.register_cmap(name, mpl.colormaps[name], override_builtin=True)
 
 
 def test_unregister_builtin_cmap():

lib/matplotlib/tests/test_ticker.py

@@ -916,12 +916,15 @@ def test_mathtext_ticks(self):
         })
 
         # Glyph warning unrelated
-        warnings.filterwarnings("ignore", category=UserWarning, message="Glyph 8722")
+        with warnings.catch_warnings():
+            warnings.filterwarnings(
+                "ignore", category=UserWarning, message="Glyph 8722"
+            )
 
-        with pytest.warns(UserWarning, match='cmr10 font should ideally'):
-            fig, ax = plt.subplots()
-            ax.set_xticks([-1, 0, 1])
-            fig.canvas.draw()
+            with pytest.warns(UserWarning, match='cmr10 font should ideally'):
+                fig, ax = plt.subplots()
+                ax.set_xticks([-1, 0, 1])
+                fig.canvas.draw()
 
     def test_cmr10_substitutions(self, caplog):
         mpl.rcParams.update({