在jupyter笔记本中将Matplotlib与PyQt5一起使用

Question

I need to create scientific plots with matplotlib in Jupyter notebook, and create them in separate windows instead of inline. I ran %matplotlib qt and got this error: ImportError: No module named PyQt4

A lot of related answers on the internet involves installing PyQt4. To give some background information, I use Anaconda to manage python modules on a Windows machine. Anaconda installs PyQt5.6.0 in its root environment by default. Downgrading this package to PyQt4 will solve the problem, however, another module in my project depends on PyQt5. I want to figure out how use matplotlib with PyQt5.

According to matploblib's tutorial , it supports PyQt5 backend. I tried to run matplotlib.rcParams['backend'] = "Qt5Agg" and matplotlib.use('Qt5Agg') before the %matplotlib qt , but got same error. Am I missing something that's so obvious to others? Helps are appreciated.

Answer 1

Thanks to @ImportanceOfBeingErnest (see comments below the question), I figured it out myself. Here is the answer for anyone who stumbled upon this question.

The method that should work for most people if you want to use PyQt5 in matplotlib to create figures in individual windows is to run matplotlib.use('Qt5Agg') then %matplotlib qt5 .

This doesn't work for me for some reason I still don't know. But the workaround is to check the following two files: /.ipython/ipython_config.py and /.ipython/ipython_kernel_config.py and make sure there is no backend preference in it. In my case, I didn't even have these two files. The problem was solved after I created them. You can create them by running ipython profile create in cmd.

If anyone have more insights on why these two files (with no uncommented content) are needed, please let me know!

Answer 2

In my ~/.config/matplotlib/matplotlibrc file at line 41 I have the following:

backend : Qt5Agg

then I usually type

matplotlib qt in a notebook or qtconsole to get external, as opposed to inline, plots