如果出现pyparsing报错
就去卸载它，可能已经安装了高版本
先去卸载试试
pip list | grep pyparsing 查看版本
pip uninstall pyparsing 卸载 如果卸载不掉，有下面的报错
pip uninstall pyparsing
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 Please upgrade your Python as Python 2.7 is no longer maintained.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.
Found existing installation: pyparsing 1.5.6
ERROR: Cannot uninstall ‘pyparsing’. It is a distutils installed project and thus we cannot accurately determine which files belong to it which would lead to only a partial uninstall.
就去/usr/lib/python2.7/site-packages/ 或 /usr/local/lib/python2.7/site-packages/ 下。搜索pyparsing，删除所有的文件
再去yum install -y pyparsing 安装一下
