Deprecation warning due to invalid escape sequences

[tirkarthi]

Description

Deprecation warnings are raised due to invalid escape sequences. This can be fixed by using raw strings or escaping the literals. pyupgrade also helps in automatic conversion : https://github.com/asottile/pyupgrade/

Steps to reproduce

./contrib/experiments/test_messaging.py:78: DeprecationWarning: invalid escape sequence \S
  m = re.match("^join (\S+)$", line)
./contrib/experiments/test_messaging.py:87: DeprecationWarning: invalid escape sequence \S
  m = re.match("^invite (\S+) (\S+)$", line)
./contrib/experiments/test_messaging.py:96: DeprecationWarning: invalid escape sequence \S
  m = re.match("^send (\S+) (.*)$", line)
./contrib/experiments/test_messaging.py:105: DeprecationWarning: invalid escape sequence \S
  m = re.match("^backfill (\S+)$", line)

[clokep]

Is there a particular way you've gone about finding these deprecation warnings? (Running the tests with specific flags or...?)

[tirkarthi]

Sorry, I forgot to include the command.

find . -iname '*.py' | grep -Ev 'vendor|example|doc|tools|sphinx' | xargs -P4 -I{} python3.8 -Wall -m py_compile {}

[tirkarthi]

Running the above command in project root should print the warnings.

[anoadragon453]

In my case (with python environments and tox directories hanging about), I needed to use the following slightly modified command:

find . -path ./env -prune -o -path ./.tox -prune -o -path ./build -prune -o -iname '*.py' | grep -Ev 'vendor|example|doc|tools|sphinx' | xargs -P4 -I{} python3.8 -Wall -m py_compile {}

but regardless, this looks useful to run on the regular, and thank you for the PR cleaning it up.

I'm interested to know whether people think this should be part of CI?

[clokep]

I'm interested to know whether people think this should be part of CI?

That was my thought. :) Might be worth filing an issue about.

[anoadragon453]

@clokep #7909