我有一个Ubuntu 16.04机器，该机器在/python/上具有多个Python 3安装，并且需要能够随意在它们之间切换。这些版本之一是Python 3.3，并且PIP直到Python 3.4.x才预安装，因此我想将PIP安装到此Python安装中。我不想使用发行软件包，因为它实际上需要集成到/python/python33安装中，我在管理此问题时遇到了麻烦：
get-pip.py试图在/usr/bin上卸载PIP的版本：
$ /tmp/get-pip.py --prefix /python/python33
Collecting pip
Using cached pip-9.0.1-py2.py3-none-any.whl
Installing collected packages: pip
Found existing installation: pip 8.1.2
Uninstalling pip-8.1.2:
Exception:
Traceback (most recent call last):
File "/tmp/tmpdgdWPZ/pip.zip/pip/basecommand.py", line 215, in main
status = self.run(options, args)
File "/tmp/tmpdgdWPZ/pip.zip/pip/commands/install.py", line 342, in run
prefix=options.prefix_path,
File "/tmp/tmpdgdWPZ/pip.zip/pip/req/req_set.py", line 778, in install
requirement.uninstall(auto_confirm=True)
File "/tmp/tmpdgdWPZ/pip.zip/pip/req/req_install.py", line 754, in uninstall
paths_to_remove.remove(auto_confirm)
File "/tmp/tmpdgdWPZ/pip.zip/pip/req/req_uninstall.py", line 115, in remove
renames(path, new_path)
File "/tmp/tmpdgdWPZ/pip.zip/pip/utils/__init__.py", line 267, in renames
shutil.move(old, new)
File "/usr/lib/python2.7/shutil.py", line 303, in move
os.unlink(src)
OSError: [Errno 13] Permission denied: '/usr/bin/pip'
You are using pip version 8.1.2, however version 9.0.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
如果我添加了 --ignore-installed，它不会出错，但仍在查看/usr/bin的pip版本（旧的8.1.2一个人抱怨的一个）：
$ /tmp/get-pip.py --ignore-installed --prefix /python/python33
Collecting pip
Using cached pip-9.0.1-py2.py3-none-any.whl
Installing collected packages: pip
Successfully installed pip-9.0.1
You are using pip version 8.1.2, however version 9.0.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
easy_install也无法工作：
$ export PYTHONPATH="$PYTHONPATH:/python/python33/"; /usr/bin/easy_install --prefix /python/python33 pip
TEST FAILED: /python/python33/lib/python2.7/site-packages does NOT support .pth files
error: bad install directory or PYTHONPATH
You are attempting to install a package to a directory that is not
on PYTHONPATH and which Python does not read ".pth" files from. The
installation directory you specified (via --install-dir, --prefix, or
the distutils default setting) was:
/python/python33/lib/python2.7/site-packages
and your PYTHONPATH environment variable currently contains:
'/pyqt/sip-4.13.1/site-packages:/pyqt/site-packages:/python/python33/'
Here are some of your options for correcting the problem:
* You can choose a different installation directory, i.e., one that is
on PYTHONPATH or supports .pth files
* You can add the installation directory to the PYTHONPATH environment
variable. (It must then also be on PYTHONPATH whenever you run
Python and want to use the package(s) you are installing.)
* You can set up the installation directory to support ".pth" files by
using one of the approaches described here:
https://pythonhosted.org/setuptools/easy_install.html#custom-installation-locations
Please make the appropriate changes for your system and try again.
为什么要安装到/python/python33/lib/python2.7/site-packages？这是PIP的Python 2版本吗？
我在这里阅读了很多相关的答案，但是到目前为止，它们都没有帮助。
我在16.04 ubuntu box上安装了python 3.5.2 an 3.6.3。
3.5.2是在/usr/bin上安装的系统python3和python3.5指向此版本
的符号链接3.6.3安装在/usr/local/binPython3.6指向此版本
对我来说，以下工作：
wget https://bootstrap.pypa.io/get-pip.py
python3.6 get-pip.py
mkdir /home/ubuntu/myproj/venv
python3.6 -m venv /home/ubuntu/myproj/venv
#Activate the venv
source /home/ubuntu/myproj/venv/bin/activate
python3现在指向我虚拟环境中的3.6。
您是如何在16.04安装Python 3.6的。我有一个伤害世界的世界，不要破坏事物。最后，我从源头构建。有关详细信息，请参见此要旨。这个问题解释了为什么。这篇博客文章给了我解决方案。