Update the `black` version and format the strings

🚀 Feature

We currently use black version 19.10b0. The idea is to upgrade to the version 21.9b0 and use the following option

black . --experimental-string-processing

to format strings.

This should be included in the script run_code_style.sh

bash ./tests/run_code_style.sh fmt

A point is to check and report the impact of the upgrade.

[vfdev-5]

in case of

# original
train_loader = idist.auto_dataloader(
    train_dataset, batch_size=config["batch_size"], num_workers=config["num_workers"], shuffle=True, drop_last=True,
)

# black
train_loader = idist.auto_dataloader(
    train_dataset,
    batch_size=config["batch_size"],
    num_workers=config["num_workers"],
    shuffle=True,
    drop_last=True,
)

the last comma after drop_last=True, makes it line by line. If you remove it, it should be unexpanded.

[vfdev-5]

@sdesrozis can you try locally that ? The last time I tried that and black reformatted a lot of code into ugly things like:

a = [
    func(
       a,
       b,
       12,
    ),
    124
]

That was principal blocker to update. If the newest version does not produce weird result and our codebase remains practially the same I’d agree to update.