MNT: simplify fallback Qt behavior

tacaswell · tacaswell · commit f43a30df48a4 · 2016-03-17T13:44:02.000-04:00
A check was added change the fall-back behavior if the backend was not
set to PyQt{4,5}, but mpl was being embedded in a larger Qt application.

The previous commit handles the cases where Qt bindings are already
imported earlier in the module so the check here can be removed.
diff --git a/lib/matplotlib/backends/qt_compat.py b/lib/matplotlib/backends/qt_compat.py
@@ -77,15 +77,12 @@
     elif rcParams['backend'] == 'Qt4Agg':
         QT_API = rcParams['backend.qt4']
     else:
-        # A different backend was specified, but we still got here because a Qt
-        # related file was imported. This is allowed, so lets try and guess
-        # what we should be using.
-        if "PyQt4" in sys.modules or "PySide" in sys.modules:
-            # PyQt4 or PySide is actually used.
-            QT_API = rcParams['backend.qt4']
-        else:
-            # This is a fallback: PyQt5
-            QT_API = rcParams['backend.qt5']
+        # A non-Qt backend was specified, no version of the Qt
+        # bindings is imported, but we still got here because a Qt
+        # related file was imported. This is allowed, fall back to Qt5
+        # using which ever binding the rparams ask for.
+
+        QT_API = rcParams['backend.qt5']
 
 # We will define an appropriate wrapper for the differing versions
 # of file dialog.
