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# Using Black with other tools

## Black compatible configurations

All of Black’s changes are harmless (or at least, they should be), but a few do conflict against other tools. It is not uncommon to be using other tools alongside Black like linters and type checkers. Some of them need a bit of tweaking to resolve the conflicts. Listed below are Black compatible configurations in various formats for the common tools out there.

Please note that Black only supports the TOML file format for its configuration (e.g. `pyproject.toml`). The provided examples are to only configure their corresponding tools, using their supported file formats.

Compatible configuration files can be found here.

### isort

isort helps to sort and format imports in your Python code. Black also formats imports, but in a different way from isort’s defaults which leads to conflicting changes.

#### Profile

Since version 5.0.0, isort supports profiles to allow easy interoperability with common code styles. You can set the black profile in any of the config files supported by isort. Below, an example for `pyproject.toml`:

    [tool.isort]
    profile = "black"

#### Custom Configuration

If you’re using an isort version that is older than 5.0.0 or you have some custom configuration for Black, you can tweak your isort configuration to make it compatible with Black. Below, an example for `.isort.cfg`:

    multi_line_output = 3
    include_trailing_comma = True
    force_grid_wrap = 0
    use_parentheses = True
    ensure_newline_before_comments = True
    line_length = 88

#### Why those options above?

Black wraps imports that surpass `line-length` by moving identifiers onto separate lines and by adding a trailing comma after each. A more detailed explanation of this behaviour can be found here.

isort’s default mode of wrapping imports that extend past the `line_length` limit is “Grid”.

    from third_party import (lib1, lib2, lib3,
                             lib4, lib5, ...)

This style is incompatible with Black, but isort can be configured to use a different wrapping mode called “Vertical Hanging Indent” which looks like this:

    from third_party import (
        lib1,
        lib2,
        lib3,
        lib4,
    )

This style is Black compatible and can be achieved by `multi-line-output = 3`. Also, as mentioned above, when wrapping long imports Black puts a trailing comma and uses parentheses. isort should follow the same behaviour and passing the options `include_trailing_comma = True` and `use_parentheses = True` configures that.

The option `force_grid_wrap = 0` is just to tell isort to only wrap imports that surpass the `line_length` limit.

Finally, isort should be told to wrap imports when they surpass Black’s default limit of 88 characters via `line_length = 88` as well as `ensure_newline_before_comments = True` to ensure spacing import sections with comments works the same as with Black.

Please note `ensure_newline_before_comments = True` only works since isort >= 5 but does not break older versions so you can keep it if you are running previous versions.

#### Formats

.isort.cfg

    [settings]
    profile = black

setup.cfg

    [isort]
    profile = black

pyproject.toml

    [tool.isort]
    profile = 'black'

.editorconfig

    [*.py]
    profile = black

### pycodestyle

pycodestyle is a code linter. It warns you of syntax errors, possible bugs, stylistic errors, etc. For the most part, pycodestyle follows PEP 8 when warning about stylistic errors. There are a few deviations that cause incompatibilities with Black.

#### Configuration

    max-line-length = 88
    ignore = E203,E701

#### Why those options above?

##### `max-line-length`

As with isort, pycodestyle should be configured to allow lines up to the length limit of `88`, Black’s default.

##### `E203`

In some cases, as determined by PEP 8, Black will enforce an equal amount of whitespace around slice operators. Due to this, pycodestyle will raise `E203 whitespace before ':'` warnings. Since this warning is not PEP 8 compliant, it should be disabled.

##### `E701` / `E704`

Black will collapse implementations of classes and functions consisting solely of `..` to a single line. This matches how such examples are formatted in PEP 8. It remains true that in all other cases Black will prevent multiple statements on the same line, in accordance with PEP 8 generally discouraging this.

However, `pycodestyle` does not mirror this logic and may raise `E701 multiple statements on one line (colon)` in this situation. Its disabled-by-default `E704 multiple statements on one line (def)` rule may also raise warnings and should not be enabled.

##### `W503`

When breaking a line, Black will break it before a binary operator. This is compliant with PEP 8 as of April 2016. There’s a disabled-by-default warning in Flake8 which goes against this PEP 8 recommendation called `W503 line break before binary operator`. It should not be enabled in your configuration. You can use its counterpart `W504 line break after binary operator` instead.

#### Formats

setup.cfg, .pycodestyle, tox.ini

    [pycodestyle]
    max-line-length = 88
    ignore = E203,E701

### Flake8

Flake8 is a wrapper around multiple linters, including pycodestyle. As such, it has many of the same issues.

#### Bugbear

It’s recommended to use the Bugbear plugin and enable its B950 check instead of using Flake8’s E501, because it aligns with Black’s 10% rule.

Install Bugbear and use the following config:

    [flake8]
    max-line-length = 80
    extend-select = B950
    extend-ignore = E203,E501,E701

#### Minimal Configuration

In cases where you can’t or don’t want to install Bugbear, you can use this minimally compatible config:

    [flake8]
    max-line-length = 88
    extend-ignore = E203,E701

#### Why those options above?

See the pycodestyle section above.

#### Formats

.flake8, setup.cfg, tox.ini

    [flake8]
    max-line-length = 88
    extend-ignore = E203,E701

### Pylint

Pylint is also a code linter like Flake8. It has many of the same checks as Flake8 and more. It particularly has more formatting checks regarding style conventions like variable naming.

#### Configuration

    max-line-length = 88

#### Why those options above?

Pylint should be configured to only complain about lines that surpass `88` characters via `max-line-length = 88`.

If using `pylint<2.6.0`, also disable `C0326` and `C0330` as these are incompatible with Black formatting and have since been removed.

#### Formats

pylintrc

    [format]
    max-line-length = 88

setup.cfg

    [pylint]
    max-line-length = 88

pyproject.toml

    [tool.pylint.format]
    max-line-length = "88"