Format code with Black and isort

[hugovk]

Fixes #401

• Format code with Black

• Add some Black-compatible config to .flake8

  • E203, W503 are not compatible with PEP 8, skip them
  • line lengths match Black's default

• sort imports with isort

  • Move isort config to the new central pyproject.toml, add new config to place nicely with Black

• Fix Flake8 errors

• Remove some Python 2 code: __cmp__ and cmp

• Add Black/isort checks to tox and the CI

To autofix code locally:

pip install -U black isort
black .
isort -y

(I'll do pre-commit in another PR.)

[codecov]

Codecov Report

Merging #411 into master will increase coverage by <.01%.
The diff coverage is 93.73%.

@@            Coverage Diff             @@
##           master     #411      +/-   ##
==========================================
+ Coverage   88.16%   88.16%   +<.01%     
==========================================
  Files          24       24              
  Lines        2382     2383       +1     
==========================================
+ Hits         2100     2101       +1     
  Misses        282      282

Impacted Files	Coverage Δ
src/tablib/formats/_csv.py	100% <100%> (ø)	⬆️
src/tablib/packages/dbfpy/dbfnew.py	97.61% <100%> (ø)	⬆️
src/tablib/formats/_html.py	100% <100%> (ø)	⬆️
src/tablib/packages/dbfpy/header.py	83.67% <100%> (ø)	⬆️
src/tablib/formats/_tsv.py	100% <100%> (ø)	⬆️
src/tablib/formats/_json.py	96.87% <100%> (ø)	⬆️
tests/test_tablib_dbfpy_packages_utils.py	100% <100%> (ø)	⬆️
src/tablib/formats/_xls.py	73.07% <100%> (ø)	⬆️
src/tablib/__init__.py	66.66% <100%> (ø)	⬆️
src/tablib/formats/_yaml.py	100% <100%> (ø)	⬆️
... and 14 more

---

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[claudep]

Thanks, but this will break (again) my PR #395. Do you think you would be able to review it before pushing this one?

[hugovk]

Sure, let's get #395 in before this. I'm not too familiar with the internals of Tablib and would rather stick to more general things like testing, so would rather someone else reviewed it. I've left a comment on the PR's issue 👍

[claudep]

I still pushed the isort part as it is less invasive that black.

[claudep]

Any idea why current master fails with isort? (cannot reproduce locally)

[hugovk]

Probably because it's missing the isort config changes in pyproject.toml, specifically:

known_third_party = ["MarkupPy", "odf", "openpyxl", "pkg_resources", "setuptools", "tablib", "xlrd", "xlwt", "yaml"]

I suggest always making a PR and only committing directly to master for very minor changes. (In fact, we could disable committing directly to master in the repo settings.)

[claudep]

Thanks for the tip and sorry for not using a PR for this change.

[hugovk]

You're welcome, and no problem :)

[hugovk]

Closing, will send new PRs.

First Black, then another for Flake8. Will be easier to review separately.