matplotlib 导入错误：无法加载请求的 Qt 绑定

Question

当我在 PyCharm 的新会话中加载 matplotlib 时，出现以下错误：

>>> import matplotlib
Backend Qt4Agg is interactive backend. Turning interactive mode on.
Failed to enable GUI event loop integration for 'qt4'
Traceback (most recent call last):
  File "/Programme/PyCharm/pycharm-community-2016.3.2/helpers/pydev/_pydev_bundle/pydev_console_utils.py", line 563, in do_enable_gui
    enable_gui(guiname)
  File "/Programme/PyCharm/pycharm-community-2016.3.2/helpers/pydev/pydev_ipython/inputhook.py", line 528, in enable_gui
    return gui_hook(app)
  File "/Programme/PyCharm/pycharm-community-2016.3.2/helpers/pydev/pydev_ipython/inputhook.py", line 195, in enable_qt4
    from pydev_ipython.inputhookqt4 import create_inputhook_qt4
  File "/Programme/PyCharm/pycharm-community-2016.3.2/helpers/pydev/_pydev_bundle/pydev_import_hook.py", line 21, in do_import
    module = self._system_import(name, *args, **kwargs)
  File "/Programme/PyCharm/pycharm-community-2016.3.2/helpers/pydev/pydev_ipython/inputhookqt4.py", line 25, in <module>
    from pydev_ipython.qt_for_kernel import QtCore, QtGui
  File "/Programme/PyCharm/pycharm-community-2016.3.2/helpers/pydev/_pydev_bundle/pydev_import_hook.py", line 21, in do_import
    module = self._system_import(name, *args, **kwargs)
  File "/Programme/PyCharm/pycharm-community-2016.3.2/helpers/pydev/pydev_ipython/qt_for_kernel.py", line 85, in <module>
    QtCore, QtGui, QtSvg, QT_API = load_qt(api_opts)
  File "/Programme/PyCharm/pycharm-community-2016.3.2/helpers/pydev/pydev_ipython/qt_loaders.py", line 281, in load_qt
    api_options))
ImportError: 
    Could not load requested Qt binding. Please ensure that
    PyQt4 >= 4.7 or PySide >= 1.0.3 is available,
    and only one is imported per session.
    Currently-imported Qt library:   None
    PyQt4 installed:                 False
    PyQt5 installed:                 True
    PySide >= 1.0.3 installed:       True
    Tried to load:                   ['pyqtdefault']

我的搜索对我没有帮助。我安装了

$ sudo apt-get install libqt5svg5*

这个问题类似于Setting up IPython Qtconsole with PyQt5，但我使用的是 Linux Kubuntu 14.4。另外，我没有安装 IPython，而是安装了 Jupyter Notebook，但是我使用 PyCharm 进行开发。

Answer 1

让 jupyter-notebook 与 PySide 一起工作时，我遇到了类似的错误。试试pip install PyQt4（最好在 virtualenv 中）。我不相信 jupyter-notebook 目前支持 Qt5。