prew is a simple tool to manage your python code.
prew init
when prew init this path, create virtualenv.
prew install <package> [<version>]
install a package in the virtualenv.
prew remove <package>
remove the package in the virtualenv.
install and remove command is record or delete dependencies in spec.yaml.
prew run
this command is run python code in current path.
when run this command, it will install dependencies in spec.yaml.
prew restore
restore command is install and init virtualenv and install dependencies based on spec.yaml.