Matplotlib与Google App Engine本地开发服务器

我想在我的Google App Engine项目中使用matplotlib。我遵循的步骤，说明这里在官方文档。我做了什么：

1）在我的应用程序根目录中创建了一个名为lib的目录。

2）在我的应用程序根目录中创建了一个文件appengine_config.py，并在其中添加了以下几行：

from google.appengine.ext import vendor
vendor.add('lib')

3）由于文档说，matplotlib的唯一版本是1.2.0，所以我在终端中执行了以下命令：

pip install -t lib matplotlib==1.2.0

文档中还有第0步，内容为

使用pip安装库，并使用供应商模块来启用从第三方库目录中导入软件包。

但我不明白这实际上意味着什么。如果这是必不可少的，请给我解释一下这是什么意思。我在stackoverflow上找到了这个答案，似乎与我所做的没什么不同。

另外，我加了

libraries:
- name: matplotlib
  version: "1.2.0"

到app.yaml。

因此，在完成所有这些步骤之后，我添加了一行

import matplotlib

到main.py并使用以下命令启动本地服务器

python ~/path/google_appengine/dev_appserver.py app.yaml

但是，当我尝试访问http：// localhost：8080 /时，会引发错误：

raise ImportError('No module named %s' % fullname)
ImportError: No module named _ctypes

如果需要，整个输出如下所示：

ERROR    2016-08-11 16:26:51,621 wsgi.py:263] 
Traceback (most recent call last):
  File "/home/magnitofon/Загрузки/google_appengine/google/appengine/runtime/wsgi.py", line 240, in Handle
    handler = _config_handle.add_wsgi_middleware(self._LoadHandler())
  File "/home/magnitofon/Загрузки/google_appengine/google/appengine/runtime/wsgi.py", line 299, in _LoadHandler
    handler, path, err = LoadObject(self._handler)
  File "/home/magnitofon/Загрузки/google_appengine/google/appengine/runtime/wsgi.py", line 85, in LoadObject
    obj = __import__(path[0])
  File "/home/magnitofon/realec-inspector/main.py", line 20, in <module>
    import matplotlib
  File "/home/magnitofon/realec-inspector/lib/matplotlib/__init__.py", line 151, in <module>
    from matplotlib.rcsetup import (defaultParams,
  File "/home/magnitofon/realec-inspector/lib/matplotlib/rcsetup.py", line 20, in <module>
    from matplotlib.colors import is_color_like
  File "/home/magnitofon/realec-inspector/lib/matplotlib/colors.py", line 52, in <module>
    import numpy as np
  File "/home/magnitofon/Загрузки/google_appengine/google/appengine/tools/devappserver2/python/sandbox.py", line 705, in load_module
    module = self._find_and_load_module(fullname, fullname, [module_path])
  File "/home/magnitofon/Загрузки/google_appengine/google/appengine/tools/devappserver2/python/sandbox.py", line 446, in _find_and_load_module
    return imp.load_module(fullname, source_file, path_name, description)
  File "/usr/local/lib/python2.7/dist-packages/numpy/__init__.py", line 180, in <module>
    from . import add_newdocs
  File "/usr/local/lib/python2.7/dist-packages/numpy/add_newdocs.py", line 13, in <module>
    from numpy.lib import add_newdoc
  File "/usr/local/lib/python2.7/dist-packages/numpy/lib/__init__.py", line 8, in <module>
    from .type_check import *
  File "/usr/local/lib/python2.7/dist-packages/numpy/lib/type_check.py", line 11, in <module>
    import numpy.core.numeric as _nx
  File "/usr/local/lib/python2.7/dist-packages/numpy/core/__init__.py", line 22, in <module>
    from . import _internal  # for freeze programs
  File "/usr/local/lib/python2.7/dist-packages/numpy/core/_internal.py", line 14, in <module>
    import ctypes
  File "/usr/lib/python2.7/ctypes/__init__.py", line 10, in <module>
    from _ctypes import Union, Structure, Array
  File "/home/magnitofon/Загрузки/google_appengine/google/appengine/tools/devappserver2/python/sandbox.py", line 963, in load_module
    raise ImportError('No module named %s' % fullname)
ImportError: No module named _ctypes

我究竟做错了什么？