Python 无法在 virtualenv 中“将 matplotlib.pyplot 作为 plt 导入”

Unable to "import matplotlib.pyplot as plt" in virtualenv

提问by Rohit

I am working with flask in a virtual environment. I was able to install matplotlib with pip, and I can import matplotlibin a Python session. However, when I import it as

我正在虚拟环境中使用烧瓶。我能够使用 pip 安装 matplotlib，并且可以import matplotlib在 Python 会话中安装。但是，当我将其导入为

matplotlib.pyplot as plt

I get the following error:

我收到以下错误：

>>> import matplotlib.pyplot as plt

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "//anaconda/envs/myenv/lib/python2.7/site-packages/matplotlib/pyplot.py", line 109, in <module>
    _backend_mod, new_figure_manager, draw_if_interactive, _show = pylab_setup()
  File "//anaconda/envs/myenv/lib/python2.7/site-packages/matplotlib/backends/__init__.py", line 32, in pylab_setup
    globals(),locals(),[backend_name],0)
  File "//anaconda/envs/myenv/lib/python2.7/site-packages/matplotlib/backends/backend_macosx.py", line 24, 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.

I am confused about why it asks me to install Python as framework. Doesn't it already exists? What does it mean to "install Python as framework", and how do I install it?

我很困惑为什么它要求我安装 Python 作为框架。不是已经存在了吗？“将 Python 安装为框架”是什么意思，我该如何安装？

采纳答案by Hercules

This solutionworked for me. If you already installed matplotlib using pip on your virtual environment, you can just type the following:

这个解决方案对我有用。如果您已经在虚拟环境中使用 pip 安装了 matplotlib，则只需键入以下内容：

$ cd ~/.matplotlib
$ nano matplotlibrc

And then, write backend: TkAggin there. If you need more information, just go to the solution link.

然后，backend: TkAgg在那里写。如果您需要更多信息，只需转到解决方案链接。

回答by user1718097

I had similar problem when I used pip to install matplotlib. By default, it installed the latest version which was 1.5.0. However, I had another virtual environment with Python 3.4 and matplotlib 1.4.3 and this environment worked fine when I imported matplotlib.pyplot. Therefore, I installed the earlier version of matplotlib using the following:

当我使用 pip 安装 matplotlib 时，我遇到了类似的问题。默认情况下，它安装了最新版本 1.5.0。但是，我有另一个使用 Python 3.4 和 matplotlib 1.4.3 的虚拟环境，当我导入 matplotlib.pyplot 时，这个环境运行良好。因此，我使用以下命令安装了早期版本的 matplotlib：

cd path_to_virtual_environment    # assume directory is called env3
env3/bin/pip install matplotlib==1.4.3

I know this is only a work-around, but it worked for me as a short-term fix.

我知道这只是一种解决方法，但它对我来说是一种短期解决方案。

回答by Bobby

Although most answers seem to point towards patching the activatescript to use the system python, I was having trouble getting that to work and an easy solution for me - though a little cringey - was to install matplotlib to the global environment and use that instead of a virtualenv instance. You can do this either by creating your virtualenv with the --system-site-packages flag like virtualenv --system-site-packages foo, or to use the universal flag when pip installing like pip install -U matplotlib.

尽管大多数答案似乎都指向修补activate脚本以使用系统 python，但我在让它工作时遇到了麻烦，对我来说一个简单的解决方案 - 尽管有点尴尬 - 是将 matplotlib 安装到全局环境并使用它而不是一个虚拟环境实例。您可以通过使用 --system-site-packages 标志创建您的 virtualenv 来做到这一点，例如virtualenv --system-site-packages foo，或者在 pip 安装时使用通用标志pip install -U matplotlib。

回答by Jonathan

You can fix this issue by using the backend Agg

您可以使用后端解决此问题 Agg

Go to User/yourname/.matplotliband open/create matplotlibrcand add the following line backend : Aggand it should work for you.

转到User/yourname/.matplotlib并打开/创建matplotlibrc并添加以下行backend : Agg，它应该适合您。

回答by JasonWayne

I got the same error, and tried Jonathan's answer:

我遇到了同样的错误，并尝试了Jonathan答案：

You can fix this issue by using the backend Agg

Go to User/yourname/.matplotliband open/create matplotlibrcand add the following line backend : Aggand it should work for you.

您可以使用后端 Agg 解决此问题

转到User/yourname/.matplotlib并打开/创建matplotlibrc并添加以下行backend : Agg，它应该适合您。

I run the program, no error, but also no plots, and I tried backend: Qt4Agg, it prints out that I haven't got PyQt4 installed.

我运行程序，没有错误，但也没有绘图，我试过了backend: Qt4Agg，它打印出我没有安装 PyQt4。

Then I tried another backend: backend: TkAgg, it works!

然后我尝试了另一个后端：backend: TkAgg，它有效！

So maybe we can try difference backends and some may work or install the requeired packages like PyQt4.

所以也许我们可以尝试不同的后端，有些可以工作或安装像 PyQt4 这样的需要的包。

Here is a sample python snippet that you can try and test matplotlib.

这是一个示例 python 片段，您可以尝试测试 matplotlib。

import matplotlib

matplotlib.use('TkAgg')
import matplotlib.pyplot as plt

plt.plot([1, 2, 3], [0, 3, 7])
plt.show()

回答by Pedro M Duarte

If you do not want to set a .matplotib/matplotlibrcconfiguration file, you can circumvent this issue by setting the 'Agg'backend at runtime right after importing matplotliband before importing matplotlib.pyplot:

如果您不想设置.matplotib/matplotlibrc配置文件，您可以通过'Agg'在导入之后matplotlib和导入之前在运行时设置后端来规避此问题matplotlib.pyplot：

In [1]: import matplotlib

In [2]: matplotlib.use('Agg')

In [3]: import matplotlib.pyplot as plt

In [4]: fig, ax = plt.subplots(1, 1)

In [5]: import numpy as np

In [6]: x = np.linspace(-1., 1.)

In [7]: y = np.sin(x)

In [8]: ax.plot(x, y)
Out[8]: [<matplotlib.lines.Line2D at 0x1057ecf10>]

In [9=]: fig.savefig('myplot.png')

回答by Mapio

A clean and easy solution is to create a kernel that sets PYTHONHOMEto VIRTUAL_ENVand then uses the system Python executable (instead of the one in the virtualenv).

一个干净而简单的解决方案是创建一个内核，该内核设置PYTHONHOME为VIRTUAL_ENV然后使用系统 Python 可执行文件（而不是 virtualenv 中的那个）。

If you want to automate the creation of such a kernel, you can use the jupyter-virtualenv-osxscript.

如果要自动创建这样的内核，可以使用jupyter-virtualenv-osx脚本。