plotting with TkAgg backend becomes unresponsive after a certain qt5agg backend import command

[js54434]

Bug report

I'm using a python library that happens to execute

from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas

When I plot using the TkAgg backend in interactive mode, the figure is unresponsive, though the data shows itself in that figure if I open a new figure.

Code for reproduction

import matplotlib.pyplot as plt
plt.ion()
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
plt.figure()
plt.plot([1], 'ko')     # plot a point

Actual outcome

The figure is unresponsive and blank, and the Mac spinning beachball symbol shows if I hover the cursor over it.

Expected outcome

The figure is plotted and responsive.

Matplotlib version

Matplotlib version 2.0.0.

python info:
Python 3.5.2 |Anaconda custom (x86_64)| (default, Jul 2 2016, 17:52:12)
[GCC 4.2.1 Compatible Apple LLVM 4.2 (clang-425.0.28)] on darwin

Mac OS X, 10.11.6

Everything was installed using anaconda.

[tacaswell]

Are you using plain python or IPython?

If the former I suspect that importing pyqt replaced the input hook from tk with the one from qt (for some more details see #4779 ). You may be able to track down how Tk sets up it's input hook and re-install it, but in general you should not expect multiple GUI frameworks to play nice in the same interactive session. The simplest solution is to just switch to using the Qt5 backend.

[js54434]

I'm using plain python.

Switching backends isn't really an option. Qt4 is apparently used with matplotlib when installed by anaconda on a mac, and using Qt5 and Qt4 together seems to be discouraged, so Qt5 probably isn't an option. As for other backends, I'm having separate issues with Qt4 and MacOSX.

[QuLogic]

Qt4 is just used by default because that's the setting the conda packagers gave it by default. You can use Qt5 pretty easily by updating conda install qt=5 and then modifying your matplotlibrc to set the Qt5Agg backend instead.

[js54434]

Just trying "conda install qt=5" gave me a package dependency error, so I ended up reinstalling anaconda, which happened to update it to python 3.6. I can now use Qt5, and I don't seem to have issues with it.

[tacaswell]

Great, closing this as resolved.