Why does pip update fail?

Question

Python

I update pip with the command: I
python -m pip install --upgrade pip
get an error:

sanetime 4.2.3 has requirement python-dateutil<2.0,>=1.5, but you'll have python-dateutil 2.8.0 which is incompatible.

What does it mean?

Answer 1

So you have a dependency conflict. You will either have to remove sanetime or roll back python-dateutil to version 1.5.

Answer 2

This means you have a version of the sanetime package installed that requires a version of python-dateutil that is not in the required pip version range.
First run
pip install -U sanetime
Then update pip