【python】升级pip后报错解决pkg_resources.DistributionNotFound: The 'pip==7.1.0' distribution was not found and is required by the application

原本使用pip版本为7.1.0，后升级至9.0.1
之后使用pip list提示pkg_resources.DistributionNotFound: The 'pip==7.1.0' distribution was not found and is required by the application

解决方法：
vim /usr/bin/pip

-------------------
#!/usr/bin/python
# EASY-INSTALL-ENTRY-SCRIPT: 'pip==7.1.0','console_scripts','pip'
__requires__ = 'pip==9.0.1'
import sys
from pkg_resources import load_entry_point

if __name__ == '__main__':
sys.exit(
load_entry_point('pip==9.0.1', 'console_scripts', 'pip')()
)
-------------------

将里面pip==后面的版本改为安装的pip版本即可