More Black! - Denser Black formatting

This is a fork of the Black code formatter

Requires Python 3.10

Black itself requires Python 3.10 or later to run. It still formats code written for Python 3.3 through 3.15.

Problem

I love Black formatting because I agree with its formatting choices, but it does have one pathology: Excessive indenting on data structures

Here is an example of Black formatting; many lines are wasted on lonely brackets:

my_method(
    [
        {
            "name": "a",
            "value": 42,
        }
    ]
)

Solution: More Black!

When there is only one property (or list item, or parameter), then do not make a new line.

my_method([{
    "name": "a",
    "value": 42,
}])

Usage

Please read the official Black documentation. The command is still black, and every option works the same.

pip install mo-black

More about this fork

Three rules differ from upstream, all of them in src/black/linegen.py and src/black/brackets.py:

A bracket whose body is a single item is not split there. _body_is_lone_item() decides the body is one thing — no comma, no operator, no and/or/if/in/is at that depth — and the split descends into it instead, leaving the brackets hugged. It applies at every depth, so nested single-key dictionaries collapse together:

schema = {"mappings": {"test": {"properties": {"one_value": {
    "type": "keyword",
    "store": True,
}}}}}

Every attribute dot is a split point, not only a dot that follows a call, so a long method chain breaks before each name.

Parentheses around something already atomic are removed. not (a) becomes not a, and foo((a), (b)) becomes foo(a, b). Every slot in the grammar's precedence cascade bottoms out at atom, so parentheses around one group nothing. Parentheses that group, build a tuple, or make a generator are left alone.

Everything else is upstream Black.

Development

Be sure you are in the mo-black main directory.

Setup virtual environment

python -m venv .venv
.venv\Scripts\activate

Install the package and its test requirements

pip install -e ".[d,jupyter]" pytest pytest-xdist

Run the tests

pytest tests

Here is the same for Linux and macOS...

python -m venv .venv
source .venv/bin/activate
pip install -e ".[d,jupyter]" pytest pytest-xdist
pytest tests

Deployment

packaging/deploy.py builds the distributions and uploads them.

python packaging/deploy.py --next-version           # what the next release would be
python packaging/deploy.py --compiled --build-only  # build it all, upload nothing
python packaging/deploy.py --compiled               # and upload

The version is never written into a file: deploy.py works out the next major.minor.%y%j and hands it to the build. Uploading happens only from master, and the tag is written afterwards, once PyPI has accepted.

--compiled additionally builds the mypyc wheels, which is what makes Black fast: one per interpreter and platform, in parallel, taking around twenty minutes. Without it you get the pure-Python wheel, which formats about 1.7x slower.