Problems using the qt5 toolkit

[Thomas Haslwanter]

Hi,
Running IPython Qt Console.exe in WinPython-64bit-3.5.2.2Qt5 I run into the following problem:

What works:

import numpy as np
import matplotlib.pyplot as plt
plt.plot(np.arange(5))
plt.show()
%matplotlib tk
plt.plot(np.arange(5))
%matplotlib inline
plt.plot(np.arange(5))

In other words, I can generate inline plots, as well as plots with the tk-framework. However, if I try

%matplotlib qt5

I get the error message

Warning: Cannot change to a different GUI toolkit: qt5. Using tk instead.

In contrast, in  WinPython-64bit-3.5.2.2 I can switch to qt4 without problems.

Could someone please explain to me why the qt5 toolkit is not supported in WinPython-64bit-3.5.2.2Qt5 ? Or in other words: what is the advantage of the WinPython-64bit-3.5.2.2Qt5 build over the WinPython-64bit-3.5.2.2 build?

Thanks, Thomas

[stonebig]

procedure:

open google

type the error message

  failed between NavigationToolbar2QT.message[str] and _show_message() 

click on first proposed (not commercial) link

https://github.com/matplotlib/matplotlib/issues/6858

follow the answer ...

tacaswell closed this on 31 Jul

... solved in coming Matplotlib2.0.0b4 (not yet released by Matplotlib)

==> Next release will be with Matplolib 2.0.0b4 or higher

[stonebig]

if you follow the fix, there is only one file changed: Lib\site-packages\matplotlib\backends\backend_qt5.py

==> you may try just to replace it in your winPython

https://github.com/matplotlib/matplotlib/pull/6854/files

[stonebig]

it doesn't work, you have to wait beta 4

[stonebig]

This default of Quality of current PyQt5 implementation is for me a sign that the community at large is trying to keep afloat too much technologies at the same time:

- the old: Python 2.7, Qt4,

- the new necessary: Python 3.5, Qt5.7 (which is truly a breaking change on Windows),

- the next: Jupyterlab, Web compilation (forgot the name), android, ...

==> The drop of Python2.7 in next Jupyter and Pandas version will hopefully help.

==> Maybe PyQt4 support should also be dropped by Jupyter next version.