上节将python的默认版本更改为python3了，我们可以直接使用python命令，该命令就是使用的python3
我们想要通过pip命令安装python扩展包，先安装pip，apt install没用，通过源码安装
去PyPI · The Python Package Index查找源码包，首先安装setuptools，再安装pip
pi@raspberrypi:~ $ wget https://files.pythonhosted.org/packages/cf/79/1a19c2f792da00cbead7b6caa176afdddf517522cb9163ce39576025b050/setuptools-57.1.0.tar.gz
pi@raspberrypi:~ $ wget https://files.pythonhosted.org/packages/4d/0c/3b63fe024414a8a48661cf04f0993d4b2b8ef92daed45636474c018cd5b7/pip-21.1.3.tar.gz
下载之后解压缩
pi@raspberrypi:~ $ tar -zxvf setuptools-57.1.0.tar.gz
pi@raspberrypi:~ $ tar -zxvf pip-21.1.3.tar.gz
进入解压缩的目录
pi@raspberrypi:~ $ cd setuptools-57.1.0
直接命令安装setuptools
pi@raspberrypi:~/setuptools-57.1.0 $ sudo python setup.py build
//由于在build时候提示错误No mudule named “distutils.util” ,故安装此部分程序，完美解决问题
pi@raspberrypi:~/setuptools-57.1.0 $ sudo apt install python3-distutils
//继续安装setuptools
pi@raspberrypi:~/setuptools-57.1.0 $ sudo python setup.py build
pi@raspberrypi:~/setuptools-57.1.0 $ sudo python setup.py install
安装pip
pi@raspberrypi:~ $ cd pip-21.1.3/ pi@raspberrypi:~/pip-21.1.3 $ sudo python setup.py build pi@raspberrypi:~/pip-21.1.3 $ sudo python setup.py install
查看pip版本
pi@raspberrypi:~/pip-21.1.3 $ pip --version pip 21.1.3 from /usr/local/lib/python3.7/dist-packages/pip-21.1.3-py3.7.egg/pip (python 3.7)
pip安装完成，可以通过pip命令安装扩展包了
pi@raspberrypi:~ $ pip install lxml
Defaulting to user installation because normal site-packages is not writeable
Collecting lxml
Downloading lxml-4.6.3-cp37-cp37m-manylinux2014_aarch64.whl (6.7 MB)
|████████████████████████████████| 6.7 MB 73 kB/s
Installing collected packages: lxml
Successfully installed lxml-4.6.3
pi@raspberrypi:~ $ ls
pip-21.1.3 pip-21.1.3.tar.gz setuptools-57.1.0 setuptools-57.1.0.tar.gz
pi@raspberrypi:~ $ python
Python 3.7.3 (default, Jan 22 2021, 20:04:44)
[GCC 8.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import lxml
>>>
没有报错，验证完成。
