FutureWarning: Possible nested set for EXTRANEOUS_WHITESPACE_REGEX

[The-Compiler]

When running pycodestyle 2.3.1 with Python 3.7, I get:

/home/florian/proj/qutebrowser/git/.tox/flake8/lib/python3.7/site-packages/pycodestyle.py:113: FutureWarning: Possible nested set at position 1
  EXTRANEOUS_WHITESPACE_REGEX = re.compile(r'[[({] | []}),;:]')

[adiroiban]

See https://docs.python.org/dev/whatsnew/3.7.html

Support of nested sets and set operations in regular expressions as ..... To avoid a warning escape them with a backslash.

Let me see if I can fix this :)

[RawrBear]

Getting the same thing in Atom while using Python 3.7.
Installed linter-flake8 and got
python37\lib\site-packages\pycodestyle.py:113: FutureWarning: Possible nested set at position 1 EXTRANEOUS_WHITESPACE_REGEX = re.compile(r'[[({] | []}),;:]')
As a python noob, I really don't know what else to add :(

[Arcanemagus]

@RawrBear Make sure that your pycodestyle version is v2.4.0 or higher as that was the first release that included the fix.

[RawrBear]

@Arcanemagus I didn't get notified about your message until now.
Thanks for the fix. I updated pycodestyle through pip which worked but broke flake8 because apparently its only compatible with version 2.3.1. so linter-flake8 is a no go right now :/

Fix one problem, find another ten lol

[jeidsath]

@RawrBear I had the same problem, so I just copied the escaped version of the line to my code:

Fixed version: https://github.com/PyCQA/pycodestyle/blob/master/pycodestyle.py#L133

[declantraynor]

@RawrBear I've found in the meantime that installing flake8 from master works around the problem:

pip install -e git+https://gitlab.com/pycqa/flake8#egg=flake8

Hope this helps.

@declantraynor Maybe I'm nitpicking but pip install -e without a specific commit is prone to changes and breakage. I think it's a good idea to pin a specific commit, the newest is 9631dac5 as of time of writing

pip install -e git+https://gitlab.com/pycqa/flake8@9631dac5#egg=flake8

[matthieugouel]

In addition you can specify the directory where flake8 will be installed with the option --src. So personally I used this command to install flake8 in my global site package :

pip3 install -e git+https://gitlab.com/pycqa/flake8@9631dac5#egg=flake
8 --src /usr/local/lib/python3.7/site-packages