使用 Homebrew 在 MacOS 上安装 Python3 出现错误“无法导入站点模块”

Question

所以我试图在 Mac OSX El Capitan 版本 10.11.6 上使用 Homebrew 重新安装 python3，但我不断收到错误。我用来安装 python3 的命令如下：

$ brew install python3

第一个命令似乎工作正常，没有抛出错误。

$ brew linkapps

第二个命令会引发以下错误：

Warning: `brew linkapps` has been deprecated and will eventually be removed!

Unfortunately `brew linkapps` cannot behave nicely with e.g. Spotlight using
either aliases or symlinks and Homebrew formulae do not build "proper" `.app`
bundles that can be relocated. Instead, please consider using `brew cask` and
migrate formulae using `.app`s to casks.
Linking: /usr/local/opt/python/IDLE.app
Linking: /usr/local/opt/python/Python Launcher.app
Linking: /usr/local/opt/python3/IDLE 3.app
Linking: /usr/local/opt/python3/Python Launcher 3.app
Linking: /usr/local/opt/qt5/libexec/Assistant-qt5.app
Linking: /usr/local/opt/qt5/libexec/Designer-qt5.app
Linking: /usr/local/opt/qt5/libexec/Linguist-qt5.app
Linking: /usr/local/opt/qt5/libexec/pixeltool-qt5.app
Linking: /usr/local/opt/qt5/libexec/qdbusviewer-qt5.app
Linking: /usr/local/opt/qt5/libexec/qml-qt5.app
Linked 10 apps to /Applications

当我尝试$ python3在终端中运行时，出现以下错误：

Failed to import the site module
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/site-packages/site.py", line 73, in <module>
    __boot()
  File "/usr/local/lib/python2.7/site-packages/site.py", line 26, in __boot
    import imp  # Avoid import loop in Python >= 3.3
  File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/imp.py", line 27, in <module>
    import tokenize
  File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/tokenize.py", line 33, in <module>
    import re
  File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/re.py", line 142, in <module>
    class RegexFlag(enum.IntFlag):
AttributeError: module 'enum' has no attribute 'IntFlag'

想要一些关于如何解决这个问题的建议。目标是我可以按照本教程中的建议安装 python3 和 opencv3，但是我坚持使用 python3 无法正常工作。

Answer 1

我通过/sf/answers/2955017761/解决了这个问题，有一个简单的unset PYTHONPATH（设置为PYTHONPATH=/usr/local/lib/python2.7/site-packages，与 python3 冲突）