Hey there! Let's unpack this since it's a common question with pip's quiet modes.

First, let's break down the quiet flags:

• -q (short for --quiet): This cuts down pip's output to only important stuff—you'll still see warnings or errors if something goes sideways, but all the regular installation logs (like "Installing collected packages..." or "Successfully installed...") get hidden.
• -qq: This cranks the quietness up a notch. It suppresses almost everything, including most warnings. The only time you'll see any output is if there's a critical failure that stops the install entirely—think network issues, missing system dependencies, or permission errors that block the process.

Now, why use -qq specifically in Jupyter Notebook?
Jupyter's output cells can get messy fast, especially when installing packages like fastbook that have a bunch of dependencies. Using -qq keeps your notebook clean—no need to scroll through dozens of lines of log messages when everything works. You'll only get notified if something breaks, which lets you focus on your code instead of sifting through install noise.

One quick thing to note: Even if you didn't find -qq explicitly called out in pip install --help, this is a standard CLI pattern. A lot of Unix/Linux tools use stacked flags for incremental effects—like -v for verbose, -vv for extra verbose, so -q and -qq follow the same logic for quieting output.

内容的提问来源于stack exchange，提问作者agent18