Make sure QApplication is quit before changing Qt framework

qt_helpers.py

@@ -225,8 +225,15 @@ def reload_qt():
     e.g. PySide if PyQt4 is loaded).
     """
 
+    # Clear any forbidden modules
     _import_hook._forbidden.clear()
 
+    # Quit app if active
+    global qapp
+    if qapp is not None:
+        qapp.quit()
+        qapp = None
+
     global QtCore
     global QtGui
 

test_switch.py

@@ -13,7 +13,7 @@
 class TestQT(object):
 
     def teardown_class(cls):
-        for m in sys.modules.keys():
+        for m in list(sys.modules.keys()):
             if m.startswith('PyQt4') or m.startswith('PySide'):
                 sys.modules.pop(m)
 
@@ -62,16 +62,13 @@ def test_load_ui_qt4(self):
         app = get_qapp()
         load_ui('test.ui')
         app.quit()
-        del app
 
     def test_load_ui_pyside(self):
         self._load_pyside()
         from qt_helpers import load_ui, get_qapp
         app = get_qapp()
         load_ui('test.ui')
-        app.exit()
         app.quit()
-        del app
 
     def test_submodule_import(self):
         self._load_qt4()
@@ -140,8 +137,6 @@ def test_launch_after_reload(self):
         time.sleep(0.1)
         app.quit()
 
-        del app
-
         os.environ['QT_API'] = qt.QT_API_PYQT4
         qt.reload_qt()
 
@@ -155,8 +150,6 @@ def test_launch_after_reload(self):
         time.sleep(0.1)
         app.quit()
 
-        del app
-
         os.environ['QT_API'] = qt.QT_API_PYSIDE
         qt.reload_qt()
 
@@ -169,5 +162,3 @@ def test_launch_after_reload(self):
         app.flush()
         time.sleep(0.1)
         app.quit()
-
-        del app