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

user2441511
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zakdances
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1 Answers1

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Type pip install -h to list help:

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

So, if you already have a package installed, it will upgrade the package for you. Without the -U switch it'll tell you the package is already installed and exit.

Each pip subcommand has its own help listing. pip -h shows you overall help, and pip [subcommand] -h gives you help for that sub command, such as install.

You can also find the full reference documentation online; the General Options section covers switches available for every pip subcommand, while each subcommand has a separate Options section to cover subcommand-specific switches; see the pip install options section, for example.

Martijn Pieters
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  • So to upgrade all packages is it no longer neccesary to run something like: `import pip from subprocess import call for dist in pip.get_installed_distributions(): call("pip install --upgrade " + dist.project_name, shell=True)` – zakdances Sep 15 '12 at 06:54
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    @yourfriendzak: Use `pip freeze --local | cut -d = -f 1 | xargs pip install -U` to upgrade *all* your packages. – Martijn Pieters Sep 15 '12 at 06:57
  • @user2357112: I actually find the online documentation the be unhelpful in this case, so I don’t think it deserves the prominence you gave it here. – Martijn Pieters May 13 '18 at 09:05