降低matplotlib版本至2.2.2

pip3 install matplotlib==2.2.2

出现新的问题，ImportError: Matplotlib qt-based backends require an external PyQt4, PyQt5,PySide or PySide2 package to be installed, but it was not found.
解决方法：安装PyQt5

pip3 install PyQt5

安装后仍出现2中的问题，应该是缺少PySide
解决方法,安装PySide

pip3 install PySide2