Python2和python3同时存在时，如何用pip给python2安装库文件

环境为 Linux Ubuntu20.04

1. 装curl，用于下载python2 的pip

$ sudo apt install curl

2. 给python2 安装pip

$ cd /usr/local/lib
$ sudo curl https://bootstrap.pypa.io/pip/2.7/get-pip.py -o get-pip.py
$ sudo python get-pip.py

# 查看pip版本

$ pip -V
pip 20.3.4 from /usr/local/lib/python2.7/dist-packages/pip (python 2.7)


# 从上面的输出确认jenkinsapi的位置，在python2.7下面

3. 用pip给python2安装库文件，以jenkinsapi为例

$ sudo python2 -m pip install jenkinsapi

# 验证jenkinsapi已经安装给了python2

$ python -V
Python 2.7.18
$ python -c "import jenkinsapi"

# 没报错，jenkinsapi的python库已经安装到python2

整个过程截屏如下以供参考：

$ sudo apt install curl
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
  libfprint-2-tod1 libfwupdplugin1 libllvm9 linux-headers-5.4.0-26 linux-headers-5.4.0-26-generic linux-image-5.4.0-26-generic
  linux-modules-5.4.0-26-generic linux-modules-extra-5.4.0-26-generic
Use 'sudo apt autoremove' to remove them.
The following NEW packages will be installed:
  curl
0 upgraded, 1 newly installed, 0 to remove and 5 not upgraded.
Need to get 161 kB of archives.
After this operation, 412 kB of additional disk space will be used.
Get:1 http://cn.archive.ubuntu.com/ubuntu focal-updates/main amd64 curl amd64 7.68.0-1ubuntu2.7 [161 kB]
Fetched 161 kB in 2s (81.2 kB/s)
Selecting previously unselected package curl.
(Reading database ... 274929 files and directories currently installed.)
Preparing to unpack .../curl_7.68.0-1ubuntu2.7_amd64.deb ...
Unpacking curl (7.68.0-1ubuntu2.7) ...
Setting up curl (7.68.0-1ubuntu2.7) ...
Processing triggers for man-db (2.9.1-1) ...


$ sudo curl https://bootstrap.pypa.io/pip/2.7/get-pip.py -o get-pip.py
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 1863k  100 1863k    0     0  2376k      0 --:--:-- --:--:-- --:--:-- 2373k


$ sudo python get-pip.py
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 Please upgrade your Python as Python 2.7 is no longer maintained. pip 21.0 will drop support for Python 2.7 in January 2021. More details about Python 2 support in pip can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support pip 21.0 will remove support for this functionality.
Collecting pip<21.0
  Downloading pip-20.3.4-py2.py3-none-any.whl (1.5 MB)
     |████████████████████████████████| 1.5 MB 666 kB/s
Collecting setuptools<45
  Downloading setuptools-44.1.1-py2.py3-none-any.whl (583 kB)
     |████████████████████████████████| 583 kB 47.9 MB/s
Collecting wheel
  Downloading wheel-0.37.1-py2.py3-none-any.whl (35 kB)
Installing collected packages: pip, setuptools, wheel
Successfully installed pip-20.3.4 setuptools-44.1.1 wheel-0.37.1


$ sudo python2 -m pip install jenkinsapi
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. pip 21.0 will drop support for Python 2.7 in January 2021. More details about Python 2 support in pip can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support pip 21.0 will remove support for this functionality.
Collecting jenkinsapi
  Using cached jenkinsapi-0.3.11-py2.py3-none-any.whl (135 kB)
Collecting pytz>=2014.4
  Downloading pytz-2022.1-py2.py3-none-any.whl (503 kB)
     |████████████████████████████████| 503 kB 577 kB/s
Collecting six>=1.10.0
  Downloading six-1.16.0-py2.py3-none-any.whl (11 kB)
Collecting requests>=2.3.0
  Downloading requests-2.27.1-py2.py3-none-any.whl (63 kB)
     |████████████████████████████████| 63 kB 3.2 MB/s
Collecting idna<3,>=2.5; python_version < "3"
  Downloading idna-2.10-py2.py3-none-any.whl (58 kB)
     |████████████████████████████████| 58 kB 9.5 MB/s
Collecting certifi>=2017.4.17
  Downloading certifi-2021.10.8-py2.py3-none-any.whl (149 kB)
     |████████████████████████████████| 149 kB 15.9 MB/s
Collecting chardet<5,>=3.0.2; python_version < "3"
  Downloading chardet-4.0.0-py2.py3-none-any.whl (178 kB)
     |████████████████████████████████| 178 kB 15.3 MB/s
Collecting urllib3<1.27,>=1.21.1
  Downloading urllib3-1.26.9-py2.py3-none-any.whl (138 kB)
     |████████████████████████████████| 138 kB 15.2 MB/s
Installing collected packages: pytz, six, idna, certifi, chardet, urllib3, requests, jenkinsapi
Successfully installed certifi-2021.10.8 chardet-4.0.0 idna-2.10 jenkinsapi-0.3.11 pytz-2022.1 requests-2.27.1 six-1.16.0 urllib3-1.26.9