我想python2.7与 一起使用virtualenv。我最近从 debian 8 升级到 debian 10。我最初有python2.7并pip安装在 debian 8 上，但也许安装过程中发生了一些事情，现在我没有pip.但我仍然安装了python2.7：
$ python --version
Python 2.7.16
所以我只是pip像这样安装：
$ cd /tmp
$ wget https://bootstrap.pypa.io/get-pip.py
$ python get-pip.py
现在我可以看到我已经安装了 pip：
$ which pip
/home/me/.local/bin/pip
$ pip --version
pip 20.0.2 from /home/me/.local/lib/python2.7/site-packages/pip (python 2.7)
首先，这是应该安装 pip 的地方吗？在我的主目录下？我是这台电脑上的唯一用户，但我不确定是否pip应该在/usr/share/或更公开的地方才能使其正常工作？我应该使用sudo python /tmp/get-pip.py安装吗pip？我不打算以 root 身份运行 python，但apt安装总是需要 root 权限，所以也许安装pip也应该有？文档没有具体说明。
无论如何，接下来我尝试更新pip到最新版本并安装virtualenv：
$ pip install -U pip
DEPRECATION: Python 2.7 reached the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 is no longer maintained. A future version of pip will drop support for Python 2.7. More details about Python 2 support in pip, can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support
Defaulting to user installation because normal site-packages is not writeable
Requirement already up-to-date: pip in ./.local/lib/python2.7/site-packages (20.0.2)
$ pip install virtualenv
DEPRECATION: Python 2.7 reached the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 is no longer maintained. A future version of pip will drop support for Python 2.7. More details about Python 2 support in pip, can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support
Defaulting to user installation because normal site-packages is not writeable
Requirement already satisfied: virtualenv in ./.local/lib/python2.7/site-packages (15.1.0)
一切看起来都不错。但是当我尝试检查virtualenv我拥有的版本时，它失败了：
$ virtualenv --version
Traceback (most recent call last):
File "/usr/local/bin/virtualenv", line 6, in <module>
from virtualenv.__main__ import run_with_catch
ImportError: No module named __main__
如果我尝试使用virtualenv它总是会抛出这些错误。
总的来说，我的问题是如何在 debian 10 上正确安装和 。python2.7我不介意卸载所有内容并重新开始（如果需要的话）。pipvirtualenv
按照指示斯蒂芬·基特在下面的答案中，我尝试卸载之前安装的pip和版本，但这会产生一些新错误。我将准确解释我所做的事情......virtualenvget-pip.py
首先卸载virtualenv：
$ pip uninstall virtualenv
DEPRECATION: Python 2.7 reached the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 is no longer maintained. A future version of pip will drop support for Python 2.7. More details about Python 2 support in pip, can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support
Found existing installation: virtualenv 15.1.0
Uninstalling virtualenv-15.1.0:
Would remove:
/home/me/.local/bin/virtualenv
/home/me/.local/lib/python2.7/site-packages/virtualenv-15.1.0.dist-info/*
/home/me/.local/lib/python2.7/site-packages/virtualenv.py
/home/me/.local/lib/python2.7/site-packages/virtualenv_support/*
Proceed (y/n)? y
Successfully uninstalled virtualenv-15.1.0
看起来不错。然后卸载pip：
$ python -m pip uninstall pip
DEPRECATION: Python 2.7 reached the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 is no longer maintained. A future version of pip will drop support for Python 2.7. More details about Python 2 support in pip, can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support
Found existing installation: pip 20.0.2
Uninstalling pip-20.0.2:
Would remove:
/home/me/.local/bin/pip
/home/me/.local/bin/pip2
/home/me/.local/bin/pip2.7
/home/me/.local/lib/python2.7/site-packages/pip-20.0.2.dist-info/*
/home/me/.local/lib/python2.7/site-packages/pip/*
Proceed (y/n)? y
Successfully uninstalled pip-20.0.2
$ pip --version
bash: /home/me/.local/bin/pip: No such file or directory
$ ls -a ~/.local/bin
. .. chardetect easy_install easy_install-2.7 flake8 pew pipenv pycodestyle pyflakes virtualenv-clone
这似乎也不错。我不确定 bash 如何知道pip应该是什么/home/me/.local/bin/pip，因为该文件不存在。也许 bash 有缓存？无论如何，接下来安装pip并virtualenv从 debian 10 存储库：
$ sudo apt install python-pip virtualenv
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
python3-distutils python3-lib2to3 python3-virtualenv
The following NEW packages will be installed:
python-pip python3-distutils python3-lib2to3 python3-virtualenv virtualenv
但是当我尝试检查virtualenv我现在拥有的版本时，它失败了：
$ virtualenv --version
Traceback (most recent call last):
File "/usr/local/bin/virtualenv", line 6, in <module>
from virtualenv.__main__ import run_with_catch
File "/usr/local/lib/python2.7/dist-packages/virtualenv/__init__.py", line 3, in <module>
from .run import cli_run
File "/usr/local/lib/python2.7/dist-packages/virtualenv/run/__init__.py", line 6, in <module>
from virtualenv.run.app_data import AppDataAction
File "/usr/local/lib/python2.7/dist-packages/virtualenv/run/app_data.py", line 8, in <module>
from virtualenv.util.lock import ReentrantFileLock
File "/usr/local/lib/python2.7/dist-packages/virtualenv/util/lock.py", line 11, in <module>
from virtualenv.util.path import Path
File "/usr/local/lib/python2.7/dist-packages/virtualenv/util/path/__init__.py", line 3, in <module>
from ._pathlib import Path
File "/usr/local/lib/python2.7/dist-packages/virtualenv/util/path/_pathlib/__init__.py", line 42, in <module>
from pathlib2 import Path
ImportError: No module named pathlib2
答案1
为了避免把事情搞砸外部virtualenvs，我建议使用打包版本：
sudo apt install python-pip virtualenv
（如果适用的话，还有python3-pipPython 3 支持）。
您可能需要删除主目录中安装的pip和版本，以及外部的任何其他版本。virtualenvPATH/usr/bin
设置 virtualenvs 时，您可以指定 Python 2.7：
virtualenv -p /usr/bin/python2.7 ...
并virtualenv会做正确的事。
答案2
经过进一步调查和讨论斯蒂芬·基特我发现我virtualenv的电脑上有 2 个不同的版本：
$ find /usr/ -iname "virtualenv" | grep bin
/usr/local/bin/virtualenv
/usr/bin/virtualenv
当我运行它时，其中的一个/usr/bin/virtualenv不会抛出错误：
$ /usr/bin/virtualenv --version
15.1.0
通过一些网络搜索，我发现其中的一个/usr/local/bin/virtualenv必须以 root 身份安装pip。所以我以piproot 身份卸载了它：
$ sudo pip uninstall virtualenv
Uninstalling virtualenv-20.0.13:
Would remove:
/usr/local/bin/virtualenv
/usr/local/lib/python2.7/dist-packages/virtualenv-20.0.13.dist-info/*
/usr/local/lib/python2.7/dist-packages/virtualenv/*
Proceed (y/n)? y
Successfully uninstalled virtualenv-20.0.13
现在一切都很好：
$ which virtualenv
/usr/bin/virtualenv
$ find /usr/ -iname "virtualenv" | grep bin
/usr/bin/virtualenv