pip安装遇到问题：You are using pip version 21.1.1； however, version 21.3.1 is available.You should consider

根据公众号教程，打开 文件资源管理器，进入到 Python（Python3.9版本）安装目录中的 scripts 下，查看是否有 pip.exe, 如果用就可以使用 Python 自带的 pip 命令进行安装。

方式：Win+R后输入三个字母CMD，然后再执行pip install beautifulsoup4的命令

C:\Users\HHH>pip install beautifulsoup4

Collecting beautifulsoup4
  Downloading beautifulsoup4-4.10.0-py3-none-any.whl (97 kB)
     |████████████████████████████████| 97 kB 182 kB/s
Collecting soupsieve>1.2
  Downloading soupsieve-2.3.1-py3-none-any.whl (37 kB)
Installing collected packages: soupsieve, beautifulsoup4
Successfully installed beautifulsoup4-4.10.0 soupsieve-2.3.1
WARNING: You are using pip version 21.1.1; however, version 21.3.1 is available.
You should consider upgrading via the 'd:\python38\python.exe -m pip install --upgrade pip' command.

出现警告字样。

查询解决教程后，发现输入pip3 install --upgrade pip可以解决。输入后拒绝访问

C:\Users\HHH>pip3 install --upgrade pip
Requirement already satisfied: pip in d:\python38\lib\site-packages (21.1.1)
Collecting pip
  Downloading pip-21.3.1-py3-none-any.whl (1.7 MB)
     |████████████████████████████████| 1.7 MB 9.4 kB/s
Installing collected packages: pip
  Attempting uninstall: pip
    Found existing installation: pip 21.1.1
    Uninstalling pip-21.1.1:
      Successfully uninstalled pip-21.1.1
ERROR: Could not install packages due to an OSError: [WinError 5] 拒绝访问。: 'D:\\Python38\\~cripts\\pip3.exe'
Consider using the `--user` option or check the permissions.

再次寻找解决办法，执行命令：

python -m pip install -U --force-reinstall pip

Collecting pip
  Using cached pip-21.3.1-py3-none-any.whl (1.7 MB)
Installing collected packages: pip
  Attempting uninstall: pip
    Found existing installation: pip 21.3.1
    Uninstalling pip-21.3.1:
      Successfully uninstalled pip-21.3.1
Successfully installed pip-21.3.1

执行成功！！！但是我发现，这是装pip，和我的目的装beautifulsoup4大相径庭！！

后来居然发现很简单的方式，先下载beautifulsoup4的安装包。然后执行命令即可。

先进这个

Beautiful Soup 4.4.0 文档 — Beautiful Soup 4.2.0 中文 文档https://beautifulsoup.readthedocs.io/zh_CN/v4.4.0/#id8

再进这个

Index of /software/BeautifulSoup/bs4/download/4.0

下载你喜欢的压缩包

解压到python38文件夹下。

我的路径是：D:\Python38\beautifulsoup4-4.1.0

 在cmd中，进入D:\Python38\beautifulsoup4-4.1.0>Python setup.py install

执行Python setup.py install显示

.......

byte-compiling D:\Python38\Lib\site-packages\bs4\tests\__init__.py to __init__.cpython-38.pyc
byte-compiling D:\Python38\Lib\site-packages\bs4\__init__.py to __init__.cpython-38.pyc
running install_egg_info
Writing D:\Python38\Lib\site-packages\beautifulsoup4-4.1.0-py3.8.egg-info

依然没有出现成功字样！

D:\Python38>pip install beautifulsoup4

没有执行成功，需要到路径下删除bs5相关文件

 一共三个哦

然后再执行就成功了

D:\Python38>pip install beautifulsoup4

成功