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 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.
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"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
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.
.isort.cfg
[settings]
profile = blacksetup.cfg
[isort]
profile = blackpyproject.toml
[tool.isort]
profile = 'black'.editorconfig
[*.py]
profile = blackpycodestyle 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.
max-line-length = 88
ignore = E203,E701
(labels/why-pycodestyle-warnings)=
As with isort, pycodestyle should be configured to allow lines up to the length limit of
88, Black's default.
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.
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.
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.
setup.cfg, .pycodestyle, tox.ini
[pycodestyle]
max-line-length = 88
ignore = E203,E701Flake8 is a wrapper around multiple linters, including pycodestyle. As such, it has many of the same issues.
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
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
See the pycodestyle section above.
.flake8, setup.cfg, tox.ini
[flake8]
max-line-length = 88
extend-ignore = E203,E701Pylint 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.
max-line-length = 88
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.
pylintrc
[format]
max-line-length = 88setup.cfg
[pylint]
max-line-length = 88pyproject.toml
[tool.pylint.format]
max-line-length = "88"