Merge pull request #2070 from QuLogic/more-exitstack

Use contextlib.ExitStack in more places

lib/cartopy/mpl/geoaxes.py

@@ -459,19 +459,19 @@ def hold_limits(self, hold=True):
             context manager exits.  Defaults to True.
 
         """
-        data_lim = self.dataLim.frozen().get_points()
-        view_lim = self.viewLim.frozen().get_points()
-        other = (self.ignore_existing_data_limits,
-                 self.get_autoscalex_on(), self.get_autoscaley_on())
-        try:
-            yield
-        finally:
+        with contextlib.ExitStack() as stack:
             if hold:
-                self.dataLim.set_points(data_lim)
-                self.viewLim.set_points(view_lim)
-                self.ignore_existing_data_limits = other[0]
-                self.set_autoscalex_on(other[1])
-                self.set_autoscaley_on(other[2])
+                stack.callback(self.dataLim.set_points,
+                               self.dataLim.frozen().get_points())
+                stack.callback(self.viewLim.set_points,
+                               self.viewLim.frozen().get_points())
+                stack.callback(setattr, self, 'ignore_existing_data_limits',
+                               self.ignore_existing_data_limits)
+                stack.callback(self.set_autoscalex_on,
+                               self.get_autoscalex_on())
+                stack.callback(self.set_autoscaley_on,
+                               self.get_autoscaley_on())
+            yield
 
     def _draw_preprocess(self, renderer):
         """

lib/cartopy/tests/io/test_downloaders.py

@@ -41,10 +41,12 @@ def config_replace(replacement_dict):
     dict with the given dictionary. Great for testing purposes!
 
     """
-    downloads_orig = cartopy.config['downloaders']
-    cartopy.config['downloaders'] = replacement_dict
-    yield
-    cartopy.config['downloaders'] = downloads_orig
+    with contextlib.ExitStack() as stack:
+        stack.callback(cartopy.config.__setitem__, 'downloaders',
+                       cartopy.config['downloaders'])
+        cartopy.config['downloaders'] = replacement_dict
+
+        yield
 
 
 @pytest.fixture
@@ -54,16 +56,16 @@ def download_to_temp(tmp_path_factory):
     which is automatically cleaned up on exit.
 
     """
-    old_downloads_dict = cartopy.config['downloaders'].copy()
-    old_dir = cartopy.config['data_dir']
+    with contextlib.ExitStack() as stack:
+        stack.callback(cartopy.config.__setitem__, 'downloaders',
+                       cartopy.config['downloaders'].copy())
+        stack.callback(cartopy.config.__setitem__, 'data_dir',
+                       cartopy.config['data_dir'])
+
+        tmp_dir = tmp_path_factory.mktemp('cartopy_data')
+        cartopy.config['data_dir'] = str(tmp_dir)
 
-    tmp_dir = tmp_path_factory.mktemp('cartopy_data')
-    cartopy.config['data_dir'] = str(tmp_dir)
-    try:
         yield tmp_dir
-    finally:
-        cartopy.config['downloaders'] = old_downloads_dict
-        cartopy.config['data_dir'] = old_dir
 
 
 def test_from_config():

lib/cartopy/tests/mpl/conftest.py

@@ -3,22 +3,23 @@
 # This file is part of Cartopy and is released under the LGPL license.
 # See COPYING and COPYING.LESSER in the root of the repository for full
 # licensing details.
+from contextlib import ExitStack
+
 import matplotlib.pyplot as plt
 import pytest
 
 
 @pytest.fixture(autouse=True)
 def mpl_test_cleanup(request):
-    """Runs tests in a context manager and closes figures after each test"""
-    try:
+    """Run tests in a context manager and close figures after each test."""
+    with ExitStack() as stack:
+        # At exit, close all open figures and switch backend back to original.
+        stack.callback(plt.switch_backend, plt.get_backend())
+
         # Run each test in a context manager so that state does not leak out
-        orig_backend = plt.get_backend()
         plt.switch_backend('Agg')
-        with plt.rc_context():
-            yield
-    finally:
-        # Closes all open figures and switches backend back to original
-        plt.switch_backend(orig_backend)
+        stack.enter_context(plt.rc_context())
+        yield
 
 
 def pytest_itemcollected(item):