显然，easy_install和pip有多个版本。看起来很乱。不管怎样，这是我在Ubuntu 12.10上安装Django for Python 2.7的方法:

$ sudo easy_install-2.7 pip
Searching for pip
Best match: pip 1.1
Adding pip 1.1 to easy-install.pth file
Installing pip-2.7 script to /usr/local/bin

Using /usr/lib/python2.7/dist-packages
Processing dependencies for pip
Finished processing dependencies for pip

$ sudo pip-2.7 install django
Downloading/unpacking django
  Downloading Django-1.5.1.tar.gz (8.0Mb): 8.0Mb downloaded
  Running setup.py egg_info for package django

    warning: no previously-included files matching '__pycache__' found under directory '*'
    warning: no previously-included files matching '*.py[co]' found under directory '*'
Installing collected packages: django
  Running setup.py install for django
    changing mode of build/scripts-2.7/django-admin.py from 644 to 755

    warning: no previously-included files matching '__pycache__' found under directory '*'
    warning: no previously-included files matching '*.py[co]' found under directory '*'
    changing mode of /usr/local/bin/django-admin.py to 755
Successfully installed django
Cleaning up...

$ python
Python 2.7.3 (default, Sep 26 2012, 21:51:14) 
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import django
>>> 

如果你同时安装了python3.6和python3.7，并且希望在默认情况下对python3.7使用pip，那么你应该这样做:

首先，确保为python3.7安装了pip

python3.7 -m pip install -U pip

现在pip3.7必须可用，因此我们编辑.bashrc

nano ~/.bashrc

向它添加下面的行

alias pip=pip3.7

为了使更改生效，在shell中输入:

source ~/.bashrc

现在如果你输入:

pip --version

你应该得到:

PIP 20.1.1 from /usr/local/lib/python3.7/dist-packages/ PIP (python 3.7)

这意味着，如果你使用，例如:

pip install <package>

它将为python3.7安装<package>

网址:https://docs.python.org/3/installing/

下面是如何为同时安装的linux, mac, posix的不同版本安装包:

python2   -m pip install SomePackage  # default Python 2
python2.7 -m pip install SomePackage  # specifically Python 2.7
python3   -m pip install SomePackage  # default Python 3
python3.4 -m pip install SomePackage  # specifically Python 3.4
python3.5 -m pip install SomePackage  # specifically Python 3.5
python3.6 -m pip install SomePackage  # specifically Python 3.6

在Windows上，将py Python启动器与-m开关结合使用:

py -2   -m pip install SomePackage  # default Python 2
py -2.7 -m pip install SomePackage  # specifically Python 2.7
py -3   -m pip install SomePackage  # default Python 3
py -3.4 -m pip install SomePackage  # specifically Python 3.4

它在windows中是这样工作的:

我将python文件的名称python.py和pythonw.exe更改为python3.py pythonw3.py 然后我在提示符中运行这个命令: Python3 -m PIP安装包

具体到windows: \path\to\python.exe -m pip install PackageName works

对于python 3和Windows操作系统，我总是使用这种语法在不同版本上安装包:

首先，我总是使用Git Bash命令提示符。

这里有一个安装urllib包的例子。

默认Python版本:(普通pip命令)

pip install urllib3

对于其他版本

py -3.8 -m pip install urllib3

python的Py => -3.8 =>的版本(我使用3.8.7版本)，但如果你使用3.7.7版本，它将是“-3.7” -m: just because or for modify PIP install urllib3: PIP正常命令