%matplotlib qt 不起作用

Question

Python 2.7.12 |Anaconda 4.2.0 (64-bit)| Spyder 3.0.1| IPython 5.1.0（在 Windows 上运行）

当通过以下方式在新窗口中请求绘图时：

%matplotlib qt

我收到一个错误：

Traceback (most recent call last):

  File "<ipython-input-2-6ad73d0e50c7>", line 1, in <module>
    get_ipython().magic(u'matplotlib qt')

  File "C:\Anaconda2\lib\site-packages\IPython\core\interactiveshell.py", line 2158, in magic
    return self.run_line_magic(magic_name, magic_arg_s)

  File "C:\Anaconda2\lib\site-packages\IPython\core\interactiveshell.py", line 2079, in run_line_magic
    result = fn(*args,**kwargs)

  File "<decorator-gen-105>", line 2, in matplotlib

  File "C:\Anaconda2\lib\site-packages\IPython\core\magic.py", line 188, in <lambda>
    call = lambda f, *a, **k: f(*a, **k)

  File "C:\Anaconda2\lib\site-packages\IPython\core\magics\pylab.py", line 100, in matplotlib
    gui, backend = self.shell.enable_matplotlib(args.gui)

  File "C:\Anaconda2\lib\site-packages\IPython\core\interactiveshell.py", line 2947, in enable_matplotlib
    pt.activate_matplotlib(backend)

  File "C:\Anaconda2\lib\site-packages\IPython\core\pylabtools.py", line 295, in activate_matplotlib
    matplotlib.pyplot.switch_backend(backend)

  File "C:\Anaconda2\lib\site-packages\matplotlib\pyplot.py", line 232, in switch_backend
    _backend_mod, new_figure_manager, draw_if_interactive, _show = pylab_setup()

  File "C:\Anaconda2\lib\site-packages\matplotlib\backends\__init__.py", line 32, in pylab_setup
    globals(),locals(),[backend_name],0)

  File "C:\Anaconda2\lib\site-packages\matplotlib\backends\backend_qt4agg.py", line 18, in <module>
    from .backend_qt5agg import FigureCanvasQTAggBase as _FigureCanvasQTAggBase

  File "C:\Anaconda2\lib\site-packages\matplotlib\backends\backend_qt5agg.py", line 16, in <module>
    from .backend_qt5 import QtCore

  File "C:\Anaconda2\lib\site-packages\matplotlib\backends\backend_qt5.py", line 31, in <module>
    from .qt_compat import QtCore, QtGui, QtWidgets, _getSaveFileName, __version__

  File "C:\Anaconda2\lib\site-packages\matplotlib\backends\qt_compat.py", line 137, in <module>
    from PyQt4 import QtCore, QtGui

ImportError: No module named PyQt4

Answer 1

我认为您的问题是由QT_API 环境变量仍设置为pyqt4（或pyside）引起的。例如，通过在 Python 提示符中键入 import os; print(os.environ.get('QT_API')) 来检查这一点。

如果是这种情况，您需要将其删除或设置为pyqt5。不知道怎么设置Windows下的环境变量google一下。

Answer 2

我使用了 import os; print(os.environ.get('QT_API'))，然后我得到了pyqt5。然后，我转到工具 -> 首选项 -> Ipython 控制台 -> 图形并选择后端 Qt5，然后重新启动 spyder，瞧，问题解决了。谢谢！！！！

Answer 3

通过将 matplotlib 从版本 matplotlib-1.5.3 升级到 matplotlib-2.2.2 为我解决了这个问题

pip install matplotlib --upgrade

Answer 4

如果您想在 Spyder 的新窗口中显示绘图，则不需要 %matplotlib qt。

相反，请转到 Spyder 中的 Tools 和 Preferences，然后在 Preferences 中单击 IPython consol。在IPython consol 中单击标签Graphics，然后在Graphics Backend 下拉列表中将Inline 更改为QT。