What does the -U option mean for installing pip -U

Question

Despite a ton of Googling, I cannot find any documents for command line options / arguments. What does pip install -U mean? Does anyone have a link to a list of pip options and arguments?

Answer 1

Type pip install -h to view the help:

-U, --upgrade Upgrade all packages to the latest available version

So, if you already have the package installed, it will update the package for you. Without the -U switch, it will tell you that the package is already installed and completed.

Each pip subcommand has its own help listing. pip -h shows general help, and pip [subcommand] -h gives you help for this helper command, such as install .