Various problems encountered in installing python3.7.3 (No module named pip) (WARNING: You are using pip version 21.2.4 upgrade pip to 21.3.1)

1、pip install pytest

2. At this point I tried python -m pip install --upgrade pip, but it doesn't work

 

 

 3. I tried a successful solution myself, first uninstall pip

4. After uninstalling, directly type the installation command python setup.py install, it will prompt No module named pip, replace it with python -m ensurepip command and it will be ok

 

 

 5. After the installation is successful, the pip version is 19.0.3, and it can be used normally after upgrading the pip version to 21.3.1