This is an ongoing series of commits that are reformatting our Python
code. Reformatting is done with `black` (23.1.0).
If you end up having problems merging this commit because you have made
changes to a python file, the best way to handle that is to run `git
checkout --ours <yourfile>` and then reformat it with black.
RFC: https://discourse.llvm.org/t/rfc-document-and-standardize-python-code-style
Differential revision: https://reviews.llvm.org/D151460
This reverts commit f775fe59640a2e837ad059a8f40e26989d4f9831.
I fixed a return type error in the original patch that was causing a test failure.
Also added a REQUIRES: python to the shell test so we'll skip this for
people who build lldb w/o Python.
Also added another test for the error printing.
