1. pip._vendor.urllib3.exceptions.ReadTimeoutError: HTTPSConnectionPool(host='files.pythonhosted.org', port=443): Read timed out
原因: 默认的pip的超时时间为15秒, 需要进行超时时间设置
pip install --default-timeout=100 SQLAlchemy==1.3.13
2. ERROR: Cannot uninstall 'requests'. 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.
解决：
sudo pip install --ignore-installed requests