pip install options unclear

Question

I saw this on a jupyter notebook:

!pip install -Uqq fastbook

! runs commands on shell. U stands for upgrade. What do the options qq mean? q stands for quiet.

Why are there two q's?

Looked up pip install --help.
Looked up User guide to no avail.

Answer 1

The option -q of pip give less output.

The Option is additive. In other words, you can use it up to 3 times (corresponding to WARNING, ERROR, and CRITICAL logging levels).

So:

• -q means display only the messages with WARNING,ERROR,CRITICAL log levels
• -qq means display only the messages with ERROR,CRITICAL log levels
• -qqq means display only the messages with CRITICAL log level

Answer 2

There are 3 logging levels, so -q can be used up to 3 times to hide these message types:

1. Warning
2. Error
3. Critical

This type of option is called "additive," meaning you can apply it more than once to tune the app settings.

So you can use -q to suppress various levels of debug output:

-q:   hide WARNING messages
-qq:  hide WARNING and ERROR messages
-qqq: hide all messages

FYI the option -v is also additive and can be used up to 3 times.

More information available at the pip reference