每当我使用pip时"No module named zlib"错误

Question

我正在使用Mac上的终端，每当我尝试使用PIP时，我都会收到以下错误消息，告诉我它找不到名为Zlib的模块：

---

$ pip --version
Traceback (most recent call last):
  File "/usr/local/lib/python3.6/site-packages/pip/_vendor/requests/packages/__init__.py", line 27, in <module>
    from . import urllib3
  File "/usr/local/lib/python3.6/site-packages/pip/_vendor/requests/packages/urllib3/__init__.py", line 8, in <module>
    from .connectionpool import (
  File "/usr/local/lib/python3.6/site-packages/pip/_vendor/requests/packages/urllib3/connectionpool.py", line 42, in <module>
    from .response import HTTPResponse
  File "/usr/local/lib/python3.6/site-packages/pip/_vendor/requests/packages/urllib3/response.py", line 3, in <module>
    import zlib
ModuleNotFoundError: No module named 'zlib'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.5/bin/pip", line 7, in <module>
    from pip import main
  File "/usr/local/lib/python3.6/site-packages/pip/__init__.py", line 21, in <module>
    from pip._vendor.requests.packages.urllib3.exceptions import DependencyWarning
  File "/usr/local/lib/python3.6/site-packages/pip/_vendor/requests/__init__.py", line 62, in <module>
    from .packages.urllib3.exceptions import DependencyWarning
  File "/usr/local/lib/python3.6/site-packages/pip/_vendor/requests/packages/__init__.py", line 29, in <module>
    import urllib3
  File "/usr/local/lib/python3.6/site-packages/urllib3/__init__.py", line 8, in <module>
    from .connectionpool import (
  File "/usr/local/lib/python3.6/site-packages/urllib3/connectionpool.py", line 36, in <module>
    from .response import HTTPResponse
  File "/usr/local/lib/python3.6/site-packages/urllib3/response.py", line 3, in <module>
    import zlib
ModuleNotFoundError: No module named 'zlib'

---

我已经阅读了几个带有相同错误消息的帖子，并尝试了他们的解决方案，包括尝试使用Homebrew安装Zlib，该ZLIB失败并更新我的Xcode开发人员工具。我还使用python get-pip.py安装了PIP，并说它已成功安装。

我需要pip的原因是要在Python 2.7上安装一个软件包，但是执行$ pip install "package-name"的错误与上面的错误相同。如果有帮助，我的机器上都安装了Python 2和3。我是PIP的新手，通常使用命令行，而且我非常困惑。如果有人能帮助我，我真的很感激。

Answer 1

这是OP。我能够解决这个问题，并希望在此处发布我的解决方案，以防其对他人有所帮助。

本质上，我认为这是因为Python2在我的机器上默认而发生的，但是默认情况下，PIP指向与Python3有关的资源或类似的资源。做pip2 --version而不是提供预期的响应。