Overview

When I try the code of the gift that uses matplotlib with python2 in the pyenv environment of Mac, it doesn't work.

From the result, install pyside2, edit the config matplotlibrc of matplotlib, and backend osx To backend qt5agg Then it worked.

environment

Mac OSX 10.15.5 Python 2.7.17 (installed with pyenv)

error contents

When I type python-code.py (pseudonym), I get the following error.

Traceback (most recent call last):
  File "python-code.py", line 60, in <module>
    import matplotlib.pyplot as plt
  File "/Users/username/.pyenv/versions/2.7.17/lib/python2.7/site-packages/matplotlib/pyplot.py", line 115, in <module>
    _backend_mod, new_figure_manager, draw_if_interactive, _show = pylab_setup()
  File "/Users/username/.pyenv/versions/2.7.17/lib/python2.7/site-packages/matplotlib/backends/__init__.py", line 63, in pylab_setup
    [backend_name], 0)
  File "/Users/username/.pyenv/versions/2.7.17/lib/python2.7/site-packages/matplotlib/backends/backend_macosx.py", line 17, in <module>
    from matplotlib.backends import _macosx
RuntimeError: Python is not installed as a framework. The Mac OS X backend will not be able to function correctly if Python is not installed as a framework. See the Python documentation for more information on installing Python as a framework on Mac OS X. Please either reinstall Python as a framework, or try one of the other backends. If you are using (Ana)Conda please install python.app and replace the use of 'python' with 'pythonw'. See 'Working with Matplotlib on OSX' in the Matplotlib FAQ for more information.

When you read

from matplotlib.backends import _macosx

As you can see, the GUI library seems to be useless.

solution

When I looked it up, it seemed like a common error, and I came up with some solutions. It seems to work with qt5agg using Qt, but another difficulty. It seems that PyQt5, which is familiar in python3, cannot be used in python2.

There seems to be an alternative, called pyside2. Put this in.

pip install pyside2

And

python -c "import matplotlib;print(matplotlib.matplotlib_fname())"

Then, check the path of matplotlibrc (matplot config file), line 42

backend      : macosx

Comment out and add qt5agg.

# backend      : macosx
backend : qt5agg

With this, the intended operation was performed safely. Congratulations.

Supplement

I tried Tkagg which uses Tk, but it didn't work.

reference

https://qiita.com/masatomix/items/03419c7ea10262da18f3 https://stackoverflow.com/questions/57238618/how-do-you-display-a-figure-in-matplotlib-using-pyside2