导入 matplotlib.pyplot 作为 plt 失败

Question

File "<stdin>", line 1, in <module>
  File "C:\Users\franc\Anaconda3\lib\site-packages\matplotlib\pyplot.py", line 32, in <module>
    import matplotlib.colorbar
  File "C:\Users\franc\Anaconda3\lib\site-packages\matplotlib\colorbar.py", line 32, in <module>
    import matplotlib.contour as contour
  File "C:\Users\franc\Anaconda3\lib\site-packages\matplotlib\contour.py", line 18, in <module>
    import matplotlib.font_manager as font_manager
  File "C:\Users\franc\Anaconda3\lib\site-packages\matplotlib\font_manager.py", line 1363, in <module>
    _rebuild()
  File "C:\Users\franc\Anaconda3\lib\site-packages\matplotlib\font_manager.py", line 1344, in _rebuild
    fontManager = FontManager()
  File "C:\Users\franc\Anaconda3\lib\site-packages\matplotlib\font_manager.py", line 978, in __init__
    ttffiles = findSystemFonts(paths) + findSystemFonts()
  File "C:\Users\franc\Anaconda3\lib\site-packages\matplotlib\font_manager.py", line 264, in findSystemFonts
    fontfiles.update(win32InstalledFonts(fontext=fontext))
TypeError: 'NoneType' object is not iterable

I've tried to uninstall and reinstall matplotlib in many ways, but I still get the above error.

Answer 1

I met this problem and fixxed it with installing the old version. Try:

pip uninstall matplotlib

pip install -v matplotlib==2.2.2

It seem that this bug casued by the incorrect use of pathlib package in matplotlib.font_manager.py