Coding style changing to black, isort, then yapf

[HYChou0515]

TL;DR

Format code in this order

1. black
2. isort
3. yapf

Test coding style in

• CI test
• pre-commit

Description

Current coding style is yapf only.
However yapf itself is not strict. (see example below)
To be more strict, but still stick to yapf style, using black first and then yapf seems a good way to go.
To make this realistic and practical, try adding them to CI test and pre-commit check.

yapf is not strict

Both style is considered fine in yapf

’single quoted’

“double quoted"