pip 设置源（推荐）

pip freeze > requirements.txt

pip install -r requirements.txt
pip install -r requirements.txt --no-cache-dir

pip uninstall package_name

pip download -r requirements.txt -d ./offline-packages
pip wheel -r requirements.txt --wheel-dir ./offline-packages

pip install ./offline-packages/package_name-version.tar.gz

pip install --no-index --find-links=./offline-installation -r requirements.txt