python - 我尝试django runserver时，Python 2.7突然不起作用:“找不到符号:__ PyErr_ReplaceException”

Question

问题
我无意中做了任何重大更改，但突然，当我尝试在本地运行django应用程序时，出现以下错误：

(awe01)MoriartyMacBookAir13:awesomeapp macuser$ foreman start
03:55:28 web.1  | started with pid 38101
03:55:29 web.1  | Traceback (most recent call last):
03:55:29 web.1  |   File "/Users/macuser/Dropbox/code/heroku/awe01/bin/gunicorn", line 5, in <module>
03:55:29 web.1  |     from pkg_resources import load_entry_point
03:55:29 web.1  |   File "/Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/site-packages/pkg_resources.py", line 22, in <module>
03:55:29 web.1  |     import zipfile
03:55:29 web.1  |   File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/zipfile.py", line 6, in <module>
03:55:29 web.1  |     import io
03:55:29 web.1  |   File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/io.py", line 51, in <module>
03:55:29 web.1  |     import _io
03:55:29 web.1  | ImportError: dlopen(/Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/lib-dynload/_io.so, 2): Symbol not found: __PyErr_ReplaceException
03:55:29 web.1  |   Referenced from: /Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/lib-dynload/_io.so
03:55:29 web.1  |   Expected in: flat namespace
03:55:29 web.1  |  in /Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/lib-dynload/_io.so
03:55:29 web.1  | exited with code 1
03:55:29 system | sending SIGTERM to all processes
SIGTERM received
(awe01)MoriartyMacBookAir13:awesomeapp macuser$

这个 foreman start命令是我如何总是在本地运行应用程序（基于heroku指令），而不是 python manage.py runserver（所以我不知道 python manage.py runserver最近是否工作过），但是现在不管怎样，错误消息（上面）对于 foreman start和 python manage.py runserver都是一样的。
即使我返回到一个更早的git提交，也会得到同样的错误，这个提交在当时是有效的，所以我不认为它是最近添加到我的代码中的新行。相反，python的设置方式似乎有所改变（如果可能的话？）
附加信息
正如 31164285
我总是在一个虚拟环境中运行项目，如您在括号中的（awe01）所示

(awe01)MoriartyMacBookAir13:awesomeapp macuser$ which python
/Users/macuser/Dropbox/code/heroku/awe01/bin/python

基于这个线程（ 31106958），下面的输出可能对某些人有用吗？

(awe01)MoriartyMacBookAir13:awesomeapp macuser$ nm /System/Library/Frameworks/Python.framework/Versions/2.7/Python | grep PyErr_ReplaceException
0000000000092b82 T __PyErr_ReplaceException

注意，如果在这个venv中输入“python”，它会告诉我使用的是2.7.6

(awe01)MoriartyMacBookAir13:awesomeapp macuser$ python
Python 2.7.6 (default, Sep  9 2014, 15:04:36) 
[GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.39)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.path
['', '/Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/site-packages/feedparser-5.1.2-py2.7.egg', '/Users/macuser/Dropbox/code/heroku/awe01/lib/python27.zip', '/Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7', '/Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/plat-darwin', '/Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/plat-mac', '/Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/plat-mac/lib-scriptpackages', '/Users/macuser/Dropbox/code/heroku/awe01/Extras/lib/python', '/Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/lib-tk', '/Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/lib-old', '/Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/lib-dynload', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-darwin', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac/lib-scriptpackages', '/Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/site-packages']

foreman start的输出

(awe01)MoriartyMacBookAir13:awesomeapp macuser$ brew config
HOMEBREW_VERSION: 0.9.5
ORIGIN: https://github.com/Homebrew/homebrew.git
HEAD: 02d219b58d254c0e8bd77a73d901b0e03af13818
Last commit: 5 hours ago
HOMEBREW_PREFIX: /usr/local
HOMEBREW_CELLAR: /usr/local/Cellar
HOMEBREW_BOTTLE_DOMAIN: https://homebrew.bintray.com
CPU: quad-core 64-bit sandybridge
OS X: 10.10.5-x86_64
Xcode: 6.3.2
CLT: N/A
Clang: 6.1 build 602
X11: N/A
System Ruby: 2.0.0-p481
Perl: /usr/bin/perl
Python: /Users/macuser/Dropbox/code/heroku/awe01/bin/python
Ruby: /usr/bin/ruby
Java: 1.8.0_40
(awe01)MoriartyMacBookAir13:awesomeapp macuser$ 

brew config的输出

(awe01)MoriartyMacBookAir13:awesomeapp macuser$ brew doctor
Please note that these warnings are just used to help the Homebrew maintainers
with debugging if you file an issue. If everything you use Homebrew for is
working fine: please don't worry and just ignore them. Thanks!

Warning: Unbrewed header files were found in /usr/local/include.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae, and may need to be deleted.

Unexpected header files:
    /usr/local/include/node/ares.h
    /usr/local/include/node/ares_version.h
    /usr/local/include/node/nameser.h
    /usr/local/include/node/node.h
    /usr/local/include/node/node_buffer.h
    /usr/local/include/node/node_internals.h
    /usr/local/include/node/node_object_wrap.h
    /usr/local/include/node/node_version.h
    /usr/local/include/node/openssl/opensslconf.h
    /usr/local/include/node/uv-private/ngx-queue.h
    /usr/local/include/node/uv-private/stdint-msvc2008.h
    /usr/local/include/node/uv-private/tree.h
    /usr/local/include/node/uv-private/uv-bsd.h
    /usr/local/include/node/uv-private/uv-darwin.h
    /usr/local/include/node/uv-private/uv-linux.h
    /usr/local/include/node/uv-private/uv-sunos.h
    /usr/local/include/node/uv-private/uv-unix.h
    /usr/local/include/node/uv-private/uv-win.h
    /usr/local/include/node/uv.h
    /usr/local/include/node/v8-debug.h
    /usr/local/include/node/v8-preparser.h
    /usr/local/include/node/v8-profiler.h
    /usr/local/include/node/v8-testing.h
    /usr/local/include/node/v8.h
    /usr/local/include/node/v8stdint.h
    /usr/local/include/node/zconf.h
    /usr/local/include/node/zlib.h

Warning: Your Xcode (6.3.2) is outdated
Please update to Xcode 6.4.
Xcode can be updated from the App Store.

Warning: Some keg-only formula are linked into the Cellar.
Linking a keg-only formula, such as gettext, into the cellar with
`brew link <formula>` will cause other formulae to detect them during
the `./configure` step. This may cause problems when compiling those
other formulae.

Binaries provided by keg-only formulae may override system binaries
with other strange results.

You may wish to `brew unlink` these brews:

    openssl

命令 brew doctor失败，出现相同的错误，但是当我直接跳入python控制台时，我可以看到哪些导入有效或无效
（此线程建议检查urllib2）

(awe01)MoriartyMacBookAir13:awesomeapp macuser$ python 
Python 2.7.6 (default, Sep  9 2014, 15:04:36) 
[GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.39)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import urllib2
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 94, in <module>
    import httplib
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/httplib.py", line 80, in <module>
    import mimetools
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/mimetools.py", line 6, in <module>
    import tempfile
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/tempfile.py", line 32, in <module>
    import io as _io
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/io.py", line 51, in <module>
    import _io
ImportError: dlopen(/Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/lib-dynload/_io.so, 2): Symbol not found: __PyErr_ReplaceException
  Referenced from: /Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/lib-dynload/_io.so
  Expected in: flat namespace
 in /Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/lib-dynload/_io.so   

迄今为止的尝试（还没有运气）
一。重新安装python
这里推荐： https://github.com/SirVer/ultisnips/issues/508
关于问题 31900156
所以我运行了以下命令：

brew uninstall python
brew update 
brew install python

它没有解决问题。
这告诉我这不是一个django或应用程序特定的问题；而是一个python问题。
下面是卸载并重新安装python后的输出；运行 python manage.py shell命令时，我得到的错误相同：

 (awe01)MoriartyMacBookAir13:awesomeapp macuser$ brew uninstall python
Uninstalling /usr/local/Cellar/python/2.7.10_2... (6194 files, 96M)
(awe01)MoriartyMacBookAir13:awesomeapp macuser$ brew update
Already up-to-date.
(awe01)MoriartyMacBookAir13:awesomeapp macuser$ brew install python
==> Downloading https://www.python.org/ftp/python/2.7.10/Python-2.7.10.tgz
Already downloaded: /Library/Caches/Homebrew/python-2.7.10.tgz
==> Downloading https://bugs.python.org/file30805/issue10910-workaround.txt
Already downloaded: /Library/Caches/Homebrew/python--patch-c075353337f9ff3ccf8091693d278782fcdff62c113245d8de43c5c7acc57daf.txt
==> Patching
patching file Include/pyport.h
Hunk #1 succeeded at 713 (offset 14 lines).
Hunk #2 succeeded at 736 (offset 14 lines).
==> ./configure --prefix=/usr/local/Cellar/python/2.7.10_2 --enable-ipv6 --datarootdir=/usr/local/Cellar/python/2.7.10_2/share --datadir=/usr/local/Cellar/python/
==> make
==> make install PYTHONAPPSDIR=/usr/local/Cellar/python/2.7.10_2
==> make frameworkinstallextras PYTHONAPPSDIR=/usr/local/Cellar/python/2.7.10_2/share/python
==> Downloading https://pypi.python.org/packages/source/s/setuptools/setuptools-18.0.1.tar.gz
Already downloaded: /Library/Caches/Homebrew/python--setuptools-18.0.1.tar.gz
==> Downloading https://pypi.python.org/packages/source/p/pip/pip-7.1.0.tar.gz
Already downloaded: /Library/Caches/Homebrew/python--pip-7.1.0.tar.gz
==> Downloading https://pypi.python.org/packages/source/w/wheel/wheel-0.24.0.tar.gz
Already downloaded: /Library/Caches/Homebrew/python--wheel-0.24.0.tar.gz
==> /usr/local/Cellar/python/2.7.10_2/bin/python -s setup.py --no-user-cfg install --force --verbose --single-version-externally-managed --record=installed.txt --
==> /usr/local/Cellar/python/2.7.10_2/bin/python -s setup.py --no-user-cfg install --force --verbose --single-version-externally-managed --record=installed.txt --
==> /usr/local/Cellar/python/2.7.10_2/bin/python -s setup.py --no-user-cfg install --force --verbose --single-version-externally-managed --record=installed.txt --
==> Caveats
Pip and setuptools have been installed. To update them
  pip install --upgrade pip setuptools

You can install Python packages with
  pip install <package>

They will install into the site-package directory
  /usr/local/lib/python2.7/site-packages

See: https://github.com/Homebrew/homebrew/blob/master/share/doc/homebrew/Homebrew-and-Python.md

.app bundles were installed.
Run `brew linkapps python` to symlink these to /Applications.
==> Summary
🍺  /usr/local/Cellar/python/2.7.10_2: 6194 files, 96M, built in 3.4 minutes
(awe01)MoriartyMacBookAir13:awesomeapp macuser$ pip install --upgrade
Traceback (most recent call last):
  File "/Users/macuser/Dropbox/code/heroku/awe01/bin/pip", line 7, in <module>
    from pip import main
  File "/Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/site-packages/pip/__init__.py", line 13, in <module>
    from pip.utils import get_installed_distributions, get_prog
  File "/Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/site-packages/pip/utils/__init__.py", line 15, in <module>
    import zipfile
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/zipfile.py", line 6, in <module>
    import io
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/io.py", line 51, in <module>
    import _io
ImportError: dlopen(/Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/lib-dynload/_io.so, 2): Symbol not found: __PyErr_ReplaceException
  Referenced from: /Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/lib-dynload/_io.so
  Expected in: flat namespace
 in /Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/lib-dynload/_io.so
(awe01)MoriartyMacBookAir13:awesomeapp macuser$ brew linkapps python
Linking /usr/local/opt/python/IDLE.app to /Applications.
Linking /usr/local/opt/python/Python Launcher.app to /Applications.
(awe01)MoriartyMacBookAir13:awesomeapp macuser$ pip install --upgrade
Traceback (most recent call last):
  File "/Users/macuser/Dropbox/code/heroku/awe01/bin/pip", line 7, in <module>
    from pip import main
  File "/Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/site-packages/pip/__init__.py", line 13, in <module>
    from pip.utils import get_installed_distributions, get_prog
  File "/Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/site-packages/pip/utils/__init__.py", line 15, in <module>
    import zipfile
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/zipfile.py", line 6, in <module>
    import io
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/io.py", line 51, in <module>
    import _io
ImportError: dlopen(/Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/lib-dynload/_io.so, 2): Symbol not found: __PyErr_ReplaceException
  Referenced from: /Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/lib-dynload/_io.so
  Expected in: flat namespace
 in /Users/macuser/Dropbox/code/heroku/awe01/lib/python2.7/lib-dynload/_io.so
(awe01)MoriartyMacBookAir13:awesomeapp macuser$ 

我特别检查urllib2的原因是基于 this comment onissue-1384
注意，此时安装的python是version pip，但当我在virtual env awe01中键入 2.7.10_2时，它仍然会将我带到一个shell，其中version是2.7.6

(awe01)MoriartyMacBookAir13:awesomeapp macuser$ python
Python 2.7.6 (default, Sep  9 2014, 15:04:36) 
[GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.39)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> 

2。尝试在虚拟环境外启动foreman
这意味着python是系统python，2.7.10

MoriartyMacBookAir13:awesomeapp macuser$ which python
/usr/bin/python

这也失败了，但是我得到一个不同的错误消息

MoriartyMacBookAir13:awesomeapp macuser$ foreman start
04:44:30 web.1  | started with pid 50330
04:44:30 web.1  | /usr/local/foreman/bin/foreman-runner: line 41: exec: gunicorn: not found
04:44:30 web.1  | exited with code 127
04:44:30 system | sending SIGTERM to all processes
SIGTERM received
MoriartyMacBookAir13:awesomeapp macuser$

有趣的是，这个 python错误不同于这个 foreman start错误：

MoriartyMacBookAir13:awesomeapp macuser$ python manage.py runserver
Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/Library/Python/2.7/site-packages/django/core/management/__init__.py", line 385, in execute_from_command_line
    utility.execute()
  File "/Library/Python/2.7/site-packages/django/core/management/__init__.py", line 345, in execute
    settings.INSTALLED_APPS
  File "/Library/Python/2.7/site-packages/django/conf/__init__.py", line 46, in __getattr__
    self._setup(name)
  File "/Library/Python/2.7/site-packages/django/conf/__init__.py", line 42, in _setup
    self._wrapped = Settings(settings_module)
  File "/Library/Python/2.7/site-packages/django/conf/__init__.py", line 98, in __init__
    % (self.SETTINGS_MODULE, e)
ImportError: Could not import settings 'shareducate.settings' (Is it on sys.path? Is there an import error in the settings file?): No module named dj_database_url
MoriartyMacBookAir13:awesomeapp macuser$ 

换言之，我的问题现在看起来就像问题 10812651，“使用runserver时，DJANGO_SETTINGS_MODULE没有定义”。对这个问题的回答归咎于 python manage.py runserver，但我没有对 context_processors做任何有意的调整。
注意，虽然 context_processors仍然失败，但如果我只键入 python manage.py shell我就可以使用python shell。。。现在的版本是 python（不是上面的2.7.6）。
另外请注意，如果urllib2是相关的（是的，我的代码中也使用了这个），现在我可以导入它而不会出现任何错误：

MoriartyMacBookAir13:awesomeapp macuser$ python
Python 2.7.10 (default, Jul 14 2015, 19:46:27) 
[GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.39)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import urllib2
>>> 

输出：
MoriartyMacBookAir13:awesomeapp macuser$nm/System/Library/Frameworks/Python.framework/Versions/2.7/Python | grep PyErr | u ReplaceException
0000000000092b82 T\u PyErr\u替换异常
与在虚拟环境中运行时完全相同。
三。openssl
因此，为什么 2.7.10在上面的openssl上显示了一个特别的注释：我试过问题 31888394中的以下3行代码

brew install openssl
brew link --force openssl
brew install python

（我认为openssl的调查路线来自于上面的urllib2检查）
似乎没什么区别。
四。尝试从2.7.10降级到2.7.9
不确定这是否会有影响，因为venv似乎是2.7.6，但当我尝试时[如github上推荐的（ issue-1367和 issue-1384以及有问题的 31888479）
brew doctor我收到错误，

Error: python does not have a version "2.7.9" in the Cellar.
Versions available: 2.7.10_2

[编辑：根据注释添加步骤5-7]
编辑：5。检查/修改路径
如 23783054和 issue-40241建议修改路径。
我从 5846204运行这个命令：

export PATH=/usr/local/bin:$PATH

由于整个设置都在工作，然后突然停止工作，我不愿意做太多的系统更改，可能会使图片复杂化。。。
编辑：6。virtualenv——清除[根据@Maikflow的评论]
导致此错误

(awe01)MoriartyMacBookAir13:heroku macuser$ deactivate
MoriartyMacBookAir13:heroku macuser$ virtualenv --clear awe01
Deleting tree awe01/lib/python2.7
Traceback (most recent call last):
  File "/usr/local/bin/virtualenv", line 11, in <module>
    sys.exit(main())
  File "/Library/Python/2.7/site-packages/virtualenv.py", line 824, in main
    symlink=options.symlink)
  File "/Library/Python/2.7/site-packages/virtualenv.py", line 984, in create_environment
    site_packages=site_packages, clear=clear, symlink=symlink))
  File "/Library/Python/2.7/site-packages/virtualenv.py", line 1145, in install_python
    rmtree(lib_dir)
  File "/Library/Python/2.7/site-packages/virtualenv.py", line 508, in rmtree
    shutil.rmtree(dir)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 247, in rmtree
    rmtree(fullname, ignore_errors, onerror)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 247, in rmtree
    rmtree(fullname, ignore_errors, onerror)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 252, in rmtree
    onerror(os.remove, fullname, sys.exc_info())
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 250, in rmtree
    os.remove(fullname)
OSError: [Errno 13] Permission denied: 'awe01/lib/python2.7/site-packages/mutagen-1.22-py2.7.egg-info/dependency_links.txt'
MoriartyMacBookAir13:heroku macuser$ 

编辑：成功
7号。使用系统的python 2.7.10创建一个新的virtualenv
[以下是@Evert的评论]

(awe01)MoriartyMacBookAir13:awe01 macuser$ deactivate
MoriartyMacBookAir13:awe01 macuser$ cd ..
MoriartyMacBookAir13:heroku macuser$ virtualenv awe02 --no-site-packages
New python executable in awe02/bin/python
Installing setuptools, pip...done.
MoriartyMacBookAir13:heroku macuser$ cd awe02
MoriartyMacBookAir13:awe02 macuser$ source bin/activate
(awe02)MoriartyMacBookAir13:awe02 macuser$ 

此时，我复制了app文件夹awesomeapp，它位于awe02文件夹中（与bin、lib和include文件夹一起）

(awe02)MoriartyMacBookAir13:awe02 macuser$ cd awesomeapp/
(awe02)MoriartyMacBookAir13:awesomeapp macuser$ pip install -r requirements.txt 

当我这样做的时候，我在心理学上犯了一堆错误
brew switch python 2.7.9和
pip install -r requirements.txt
但在我永远放弃编程之前，我试着
warning: unused function 'Dprintf'
而且有效！

(awe02)MoriartyMacBookAir13:awesomeapp macuser$ foreman start
16:28:16 web.1  | started with pid 14174
16:28:16 web.1  | 2015-08-22 16:28:16 [14174] [INFO] Starting gunicorn 19.0.0
16:28:16 web.1  | 2015-08-22 16:28:16 [14174] [INFO] Listening at: http://0.0.0.0:5000 (14174)
16:28:16 web.1  | 2015-08-22 16:28:16 [14174] [INFO] Using worker: sync
16:28:16 web.1  | 2015-08-22 16:28:16 [14177] [INFO] Booting worker with pid: 14177

这是Python2.7.10

(awe02)MoriartyMacBookAir13:awesomeapp macuser$ python manage.py shell
Python 2.7.10 (default, Jul 14 2015, 19:46:27) 
[GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.39)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>> import urllib2
>>> 

类似地 warning: implicit conversion loses integer precision: 'long' to 'int'也能工作：）
其他想法
我想我已经把OSX升级到10.10.5版本了，自从上次 foreman start工作以来。系统是否可能更新了一些核心文件？
谢谢
我仍然在自学python/django，所以我的知识有些欠缺。。。任何解决问题的方法或技巧都会非常感谢。

Answer 1

Maikflow的解决方案对我有效：
重新启动virtualenv:virtualenv --clear venv