Changing IPython graphics backend to "Qt" will result in error when using Qt5

[yw5aj]

Dear all,

Thanks to @stonebig for catching the bug on discussion at https://groups.google.com/forum/?fromgroups#!topic/winpython/QnSEg4hKxYE

Environment: Win 7 64 bit (I don't think it matters though)
Python 3.4 64 bit
Spyder 3.0.0dev (using Qt5)

How to reproduce:

Open spyder -> Tools -> Preferences -> IPython console -> Graphics -> Change the Backend from "Inline" to "Qt" -> restart spyder -> in the IPython QtConsole, enter import matplotlib.pyplot as plt

Error:

In [1]: import matplotlib.pyplot as plt

Traceback (most recent call last):



File "<ipython-input-1-eff513f636fd>", line 1, in <module>

import matplotlib.pyplot as plt



File "X:\WinPython3Qt5\python-3.4.3.amd64\lib\site-packages\matplotlib\pyplot.py", line 114, in <module>

_backend_mod, new_figure_manager, draw_if_interactive, _show = pylab_setup()



File "X:\WinPython3Qt5\python-3.4.3.amd64\lib\site-packages\matplotlib\backends\__init__.py", line 32, in pylab_setup

globals(),locals(),[backend_name],0)



File "X:\WinPython3Qt5\python-3.4.3.amd64\lib\site-packages\matplotlib\backends\backend_qt4agg.py", line 18, in <module>

from .backend_qt5agg import FigureCanvasQTAggBase as _FigureCanvasQTAggBase



File "X:\WinPython3Qt5\python-3.4.3.amd64\lib\site-packages\matplotlib\backends\backend_qt5agg.py", line 15, in <module>

from .backend_qt5 import QtCore



File "X:\WinPython3Qt5\python-3.4.3.amd64\lib\site-packages\matplotlib\backends\backend_qt5.py", line 31, in <module>

from .qt_compat import QtCore, QtGui, QtWidgets, _getSaveFileName, __version__



File "X:\WinPython3Qt5\python-3.4.3.amd64\lib\site-packages\matplotlib\backends\qt_compat.py", line 124, in <module>

from PyQt4 import QtCore, QtGui



ImportError: No module named 'PyQt4'

stonebig pointed out that why this happend:

Doing this change, you get in the"spyder.ini file:
ets_backend = qt4

[ccordoba12]

@stonebig, what do you think we need to do to fix this problem? Removing the ets_backend option?

[stonebig]

Hi Carlos,

I don't feel expert on this.

I would suggest that this option (and current 'Qt4' value), if kept, should be understood as "use the default Qt", this one being Qt4 or Qt5.

Qt4 and Python 2.7 / 3.3 are already out of my (maintenance) mind, so you may as well switch to Qt5 only on this option.

[ccordoba12]

So ETS is available for Qt5 too?

[ccordoba12]

I think last time I checked it wasn't

[stonebig]

What is ETS ?

[ccordoba12]

@stonebig, don't worry. I found where the error was (and it wasn't related to ETS = Entought Tool Suite).

[stonebig]

great !

[stonebig]

hope you will soon do a 3.0.0 beta2 to celebrate this

[ccordoba12]

Yep, I only have to solve issue #2748 before releasing it.

[stonebig]

(silent hope)