linters and formatters

[wwade]

these day, I think the killer combo is: pipenv, python 3.7, pre-commit: flake8, black, mypy, and pyupgrade and isort

repos:
- repo: https://github.com/pre-commit/pre-commit-hooks
  rev: v2.3.0
  hooks:
  - id: check-yaml
  - id: end-of-file-fixer
  - id: trailing-whitespace
  - id: check-docstring-first
  - id: flake8
    additional_dependencies: ["flake8-bugbear==19.3.0"]
- repo: https://github.com/python/black
  rev: stable
  hooks:
  - id: black
    language_version: python3
- repo: https://github.com/pre-commit/mirrors-isort
  rev: ''  # Use the revision sha / tag you want to point at
  hooks:
  - id: isort
- repo: https://github.com/pre-commit/mirrors-mypy
  rev: v0.720
  hooks:
  - id: mypy
- repo: https://github.com/asottile/pyupgrade
  rev: v1.23.0
  hooks:
  - id: pyupgrade
    args: ["--py3-plus"]

for the .pre-commit-config.yaml

[settings]
multi_line_output=3
include_trailing_comma=True
force_grid_wrap=0
use_parentheses=True
line_length=88

for .isort.cfg (compatible with black)

[flake8]
ignore = E203, E266, E501, W503
max-line-length = 80
max-complexity = 18
select = B,C,E,F,W,T4,B9

for the .flake8