Apply black formatter

[MarcoGorelli]

xref #4108 (comment)

Reviewing PRs which change code and change formatting can be tricky, so my suggestion is to apply black to batches of 10-15 files at a time, merge those in, and then add black to .pre-commit-config.yaml.

This would make for a good beginner-friendly issue. Make sure you're using black version 20.8b1 for this.

See #4110 for an example of how to open a PR for this

EDIT

have removed the list of files as it looks like existing PRs might be enough to close this off. Please see #4095 for a similar issue to tackle

EDIT2

As of 2020-10-08, existing PRs should be enough to address all files. To close this issue, a pre-commit hook should be added

[aliakbars]

I'd like to help on this. Are there prioritised files?

[MarcoGorelli]

@aliakbars that's great! I don't think there's any prioritisation, no

[aliakbars]

@MarcoGorelli Will the above checklist get updates automatically?

[MarcoGorelli]

Nope, been doing it manually do far

[satrio-hw]

Hi, I'd like to help.. I'm working on :

• pymc3/tests/test_shape_handling.py
• pymc3/tests/test_ode.py
• pymc3/tests/test_text_backend.py
• pymc3/tests/test_tracetab.py
• pymc3/tests/test_tuning.py
• pymc3/tests/test_quadpotential.py
• pymc3/tests/test_updates.py
• pymc3/tests/test_types.py
• pymc3/tests/test_mixture.py
• pymc3/tests/test_util.py