The uncompromising code formatter.
Project description
The Uncompromising Code Formatter
“Any color you like.”
Black is the uncompromising Python code formatter. By using it, you agree to cede
control over minutiae of hand-formatting. In return, Black gives you speed,
determinism, and freedom from pycodestyle
nagging about formatting. You will save time
and mental energy for more important matters.
Blackened code looks the same regardless of the project you're reading. Formatting becomes transparent after a while and you can focus on the content instead.
Black makes code review faster by producing the smallest diffs possible.
Try it out now using the Black Playground. Watch the PyCon 2019 talk to learn more.
Contents: Installation and usage | Code style | Pragmatism | pyproject.toml | Editor integration | blackd | black-primer | Version control integration | GitHub Actions | Ignoring unmodified files | Used by | Testimonials | Show your style | Contributing | Change log | Authors
Installation and usage
Installation
Black can be installed by running pip install black
. It requires Python 3.6.2+ to
run. If you want to format Python 2 code as well, install with
pip install black[python2]
.
Install from GitHub
If you can't wait for the latest hotness and want to install from GitHub, use:
pip install git+git://github.com/psf/black
Usage
To get started right away with sensible defaults:
black {source_file_or_directory}
You can run Black as a package if running it as a script doesn't work:
python -m black {source_file_or_directory}
Command line options
Black doesn't provide many options. You can list them by running black --help
:
Usage: black [OPTIONS] [SRC]...
The uncompromising code formatter.
Options:
-c, --code TEXT Format the code passed in as a string.
-l, --line-length INTEGER How many characters per line to allow.
[default: 88]
-t, --target-version [py27|py33|py34|py35|py36|py37|py38|py39]
Python versions that should be supported by
Black's output. [default: per-file auto-
detection]
--pyi Format all input files like typing stubs
regardless of file extension (useful when
piping source on standard input).
-S, --skip-string-normalization
Don't normalize string quotes or prefixes.
-C, --skip-magic-trailing-comma
Don't use trailing commas as a reason to
split lines.
--check Don't write the files back, just return the
status. Return code 0 means nothing would
change. Return code 1 means some files
would be reformatted. Return code 123 means
there was an internal error.
--diff Don't write the files back, just output a
diff for each file on stdout.
--color / --no-color Show colored diff. Only applies when
`--diff` is given.
--fast / --safe If --fast given, skip temporary sanity
checks. [default: --safe]
--include TEXT A regular expression that matches files and
directories that should be included on
recursive searches. An empty value means
all files are included regardless of the
name. Use forward slashes for directories
on all platforms (Windows, too). Exclusions
are calculated first, inclusions later.
[default: \.pyi?$]
--exclude TEXT A regular expression that matches files and
directories that should be excluded on
recursive searches. An empty value means no
paths are excluded. Use forward slashes for
directories on all platforms (Windows, too).
Exclusions are calculated first, inclusions
later. [default: /(\.direnv|\.eggs|\.git|\.
hg|\.mypy_cache|\.nox|\.tox|\.venv|venv|\.sv
n|_build|buck-out|build|dist)/]
--extend-exclude TEXT Like --exclude, but adds additional files
and directories on top of the excluded
ones (useful if you simply want to add to
the default).
--force-exclude TEXT Like --exclude, but files and directories
matching this regex will be excluded even
when they are passed explicitly as
arguments.
--stdin-filename TEXT The name of the file when passing it through
stdin. Useful to make sure Black will
respect --force-exclude option on some
editors that rely on using stdin.
-q, --quiet Don't emit non-error messages to stderr.
Errors are still emitted; silence those with
2>/dev/null.
-v, --verbose Also emit messages to stderr about files
that were not changed or were ignored due to
exclusion patterns.
--version Show the version and exit.
--config FILE Read configuration from FILE path.
-h, --help Show this message and exit.
Black is a well-behaved Unix-style command-line tool:
- it does nothing if no sources are passed to it;
- it will read from standard input and write to standard output if
-
is used as the filename; - it only outputs messages to users on standard error;
- exits with code 0 unless an internal error occurred (or
--check
was used).
Using Black with other tools
While Black enforces formatting that conforms to PEP 8, other tools may raise warnings about Black's changes or will overwrite Black's changes. A good example of this is isort. Since Black is barely configurable, these tools should be configured to neither warn about nor overwrite Black's changes.
Actual details on Black compatible configurations for various tools can be found in compatible_configs.
Migrating your code style without ruining git blame
A long-standing argument against moving to automated code formatters like Black is
that the migration will clutter up the output of git blame
. This was a valid argument,
but since Git version 2.23, Git natively supports
ignoring revisions in blame
with the --ignore-rev
option. You can also pass a file listing the revisions to ignore
using the --ignore-revs-file
option. The changes made by the revision will be ignored
when assigning blame. Lines modified by an ignored revision will be blamed on the
previous revision that modified those lines.
So when migrating your project's code style to Black, reformat everything and commit the changes (preferably in one massive commit). Then put the full 40 characters commit identifier(s) into a file.
# Migrate code style to Black
5b4ab991dede475d393e9d69ec388fd6bd949699
Afterwards, you can pass that file to git blame
and see clean and meaningful blame
information.
$ git blame important.py --ignore-revs-file .git-blame-ignore-revs
7a1ae265 (John Smith 2019-04-15 15:55:13 -0400 1) def very_important_function(text, file):
abdfd8b0 (Alice Doe 2019-09-23 11:39:32 -0400 2) text = text.lstrip()
7a1ae265 (John Smith 2019-04-15 15:55:13 -0400 3) with open(file, "r+") as f:
7a1ae265 (John Smith 2019-04-15 15:55:13 -0400 4) f.write(formatted)
You can even configure git
to automatically ignore revisions listed in a file on every
call to git blame
.
$ git config blame.ignoreRevsFile .git-blame-ignore-revs
The one caveat is that GitHub and GitLab do not yet support ignoring revisions using their native UI of blame. So blame information will be cluttered with a reformatting commit on those platforms. (If you'd like this feature, there's an open issue for GitLab and please let GitHub know!)
NOTE: This is a beta product
Black is already successfully used by many projects, small and big. It also sports a decent test suite. However, it is still very new. Things will probably be wonky for a while. This is made explicit by the "Beta" trove classifier, as well as by the "b" in the version number. What this means for you is that until the formatter becomes stable, you should expect some formatting to change in the future. That being said, no drastic stylistic changes are planned, mostly responses to bug reports.
Also, as a safety measure which slows down processing, Black will check that the
reformatted code still produces a valid AST that is effectively equivalent to the
original (see the
Pragmatism
section for details). If you're feeling confident, use --fast
.
The Black code style
Black is a PEP 8 compliant opinionated formatter. Black reformats entire files in
place. It is not configurable. It doesn't take previous formatting into account. Your
main option of configuring Black is that it doesn't reformat blocks that start with
# fmt: off
and end with # fmt: on
, or lines that ends with # fmt: skip
. Pay
attention that # fmt: on/off
have to be on the same level of indentation. To learn
more about Black's opinions, to go
the_black_code_style.
Please refer to this document before submitting an issue. What seems like a bug might be intended behaviour.
Pragmatism
Early versions of Black used to be absolutist in some respects. They took after its
initial author. This was fine at the time as it made the implementation simpler and
there were not many users anyway. Not many edge cases were reported. As a mature tool,
Black does make some exceptions to rules it otherwise holds. This
section
of the_black_code_style
describes what those exceptions are and why this is the case.
Please refer to this document before submitting an issue just like with the document above. What seems like a bug might be intended behaviour.
pyproject.toml
Black is able to read project-specific default values for its command line options
from a pyproject.toml
file. This is especially useful for specifying custom
--include
and --exclude
/--extend-exclude
patterns for your project.
Pro-tip: If you're asking yourself "Do I need to configure anything?" the answer is "No". Black is all about sensible defaults.
What on Earth is a pyproject.toml
file?
PEP 518 defines pyproject.toml
as a
configuration file to store build system requirements for Python projects. With the help
of tools like Poetry or
Flit it can fully replace the need for
setup.py
and setup.cfg
files.
Where Black looks for the file
By default Black looks for pyproject.toml
starting from the common base directory of
all files and directories passed on the command line. If it's not there, it looks in
parent directories. It stops looking when it finds the file, or a .git
directory, or a
.hg
directory, or the root of the file system, whichever comes first.
If you're formatting standard input, Black will look for configuration starting from the current working directory.
You can use a "global" configuration, stored in a specific location in your home directory. This will be used as a fallback configuration, that is, it will be used if and only if Black doesn't find any configuration as mentioned above. Depending on your operating system, this configuration file should be stored as:
- Windows:
~\.black
- Unix-like (Linux, MacOS, etc.):
$XDG_CONFIG_HOME/black
(~/.config/black
if theXDG_CONFIG_HOME
environment variable is not set)
Note that these are paths to the TOML file itself (meaning that they shouldn't be named
as pyproject.toml
), not directories where you store the configuration. Here, ~
refers to the path to your home directory. On Windows, this will be something like
C:\\Users\UserName
.
You can also explicitly specify the path to a particular file that you want with
--config
. In this situation Black will not look for any other file.
If you're running with --verbose
, you will see a blue message if a file was found and
used.
Please note blackd
will not use pyproject.toml
configuration.
Configuration format
As the file extension suggests, pyproject.toml
is a
TOML file. It contains separate sections for
different tools. Black is using the [tool.black]
section. The option keys are the
same as long names of options on the command line.
Note that you have to use single-quoted strings in TOML for regular expressions. It's
the equivalent of r-strings in Python. Multiline strings are treated as verbose regular
expressions by Black. Use [ ]
to denote a significant space character.
Example pyproject.toml
[tool.black]
line-length = 88
target-version = ['py37']
include = '\.pyi?$'
extend-exclude = '''
# A regex preceded with ^/ will apply only to files and directories
# in the root of the project.
^/foo.py # exclude a file named foo.py in the root of the project (in addition to the defaults)
'''
Lookup hierarchy
Command-line options have defaults that you can see in --help
. A pyproject.toml
can
override those defaults. Finally, options provided by the user on the command line
override both.
Black will only ever use one pyproject.toml
file during an entire run. It doesn't
look for multiple files, and doesn't compose configuration from different levels of the
file hierarchy.
Editor integration
Black can be integrated into many editors with plugins. They let you run Black on your code with the ease of doing it in your editor. To get started using Black in your editor of choice, please see editor_integration.
Patches are welcome for editors without an editor integration or plugin! More information can be found in editor_integration.
blackd
blackd
is a small HTTP server that exposes Black's functionality over a simple
protocol. The main benefit of using it is to avoid paying the cost of starting up a new
Black process every time you want to blacken a file. Please refer to
blackd to get the ball
rolling.
black-primer
black-primer
is a tool built for CI (and humans) to have Black --check
a number of
(configured in primer.json
) Git accessible projects in parallel.
black_primer has more
information regarding its usage and configuration.
(A PR adding Mercurial support will be accepted.)
Version control integration
Use pre-commit. Once you
have it installed, add this to the
.pre-commit-config.yaml
in your repository:
repos:
- repo: https://github.com/psf/black
rev: 20.8b1 # Replace by any tag/version: https://github.com/psf/black/tags
hooks:
- id: black
language_version: python3 # Should be a command that runs python3.6+
Then run pre-commit install
and you're ready to go.
Avoid using args
in the hook. Instead, store necessary configuration in
pyproject.toml
so that editors and command-line usage of Black all behave consistently
for your project. See Black's own
pyproject.toml for an
example.
If you're already using Python 3.7, switch the language_version
accordingly. Finally,
stable
is a branch that tracks the latest release on PyPI. If you'd rather run on
master, this is also an option.
GitHub Actions
Create a file named .github/workflows/black.yml
inside your repository with:
name: Lint
on: [push, pull_request]
jobs:
lint:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- uses: actions/setup-python@v2
- uses: psf/black@stable
with:
args: ". --check"
Inputs
black_args
optional: Black input arguments. Defaults to . --check --diff
.
Ignoring unmodified files
Black remembers files it has already formatted, unless the --diff
flag is used or
code is passed via standard input. This information is stored per-user. The exact
location of the file depends on the Black version and the system on which Black is
run. The file is non-portable. The standard location on common operating systems is:
- Windows:
C:\\Users\<username>\AppData\Local\black\black\Cache\<version>\cache.<line-length>.<file-mode>.pickle
- macOS:
/Users/<username>/Library/Caches/black/<version>/cache.<line-length>.<file-mode>.pickle
- Linux:
/home/<username>/.cache/black/<version>/cache.<line-length>.<file-mode>.pickle
file-mode
is an int flag that determines whether the file was formatted as 3.6+ only,
as .pyi, and whether string normalization was omitted.
To override the location of these files on macOS or Linux, set the environment variable
XDG_CACHE_HOME
to your preferred location. For example, if you want to put the cache
in the directory you're running Black from, set XDG_CACHE_HOME=.cache
. Black will
then write the above files to .cache/black/<version>/
.
Used by
The following notable open-source projects trust Black with enforcing a consistent code style: pytest, tox, Pyramid, Django Channels, Hypothesis, attrs, SQLAlchemy, Poetry, PyPA applications (Warehouse, Bandersnatch, Pipenv, virtualenv), pandas, Pillow, every Datadog Agent Integration, Home Assistant, Zulip.
The following organizations use Black: Facebook, Dropbox, Mozilla, Quora.
Are we missing anyone? Let us know.
Testimonials
Dusty Phillips, writer:
Black is opinionated so you don't have to be.
Hynek Schlawack, creator of attrs
, core developer of
Twisted and CPython:
An auto-formatter that doesn't suck is all I want for Xmas!
Carl Meyer, Django core developer:
At least the name is good.
Kenneth Reitz, creator of requests
and
pipenv
:
This vastly improves the formatting of our code. Thanks a ton!
Show your style
Use the badge in your project's README.md:
[![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/psf/black)
Using the badge in README.rst:
.. image:: https://img.shields.io/badge/code%20style-black-000000.svg
:target: https://github.com/psf/black
License
MIT
Contributing to Black
In terms of inspiration, Black is about as configurable as gofmt. This is deliberate.
Bug reports and fixes are always welcome! However, before you suggest a new feature or configuration knob, ask yourself why you want it. If it enables better integration with some workflow, fixes an inconsistency, speeds things up, and so on - go for it! On the other hand, if your answer is "because I don't like a particular formatting" then you're not ready to embrace Black yet. Such changes are unlikely to get accepted. You can still try but prepare to be disappointed.
More details can be found in CONTRIBUTING.
Change log
The log's become rather long. It moved to its own file.
See CHANGES.
Authors
Glued together by Łukasz Langa.
Maintained with Carol Willing, Carl Meyer, Jelle Zijlstra, Mika Naylor, Zsolt Dollenstein, Cooper Lees, and Richard Si.
Multiple contributions by:
- Abdur-Rahmaan Janhangeer
- Adam Johnson
- Adam Williamson
- Alexander Huynh
- Alex Vandiver
- Allan Simon
- Anders-Petter Ljungquist
- Andrew Thorp
- Andrew Zhou
- Andrey
- Andy Freeland
- Anthony Sottile
- Arjaan Buijk
- Arnav Borbornah
- Artem Malyshev
- Asger Hautop Drewsen
- Augie Fackler
- Aviskar KC
- Batuhan Taşkaya
- Benjamin Wohlwend
- Benjamin Woodruff
- Bharat Raghunathan
- Brandt Bucher
- Brett Cannon
- Bryan Bugyi
- Bryan Forbes
- Calum Lind
- Charles
- Charles Reid
- Christian Clauss
- Christian Heimes
- Chuck Wooters
- Chris Rose
- Codey Oxley
- Cong
- Cooper Ry Lees
- Dan Davison
- Daniel Hahler
- Daniel M. Capella
- Daniele Esposti
- David Hotham
- David Lukes
- David Szotten
- Denis Laxalde
- Douglas Thor
- dylanjblack
- Eli Treuherz
- Emil Hessman
- Felix Kohlgrüber
- Florent Thiery
- Francisco
- Giacomo Tagliabue
- Greg Gandenberger
- Gregory P. Smith
- Gustavo Camargo
- hauntsaninja
- Hadi Alqattan
- Heaford
- Hugo Barrera
- Hugo van Kemenade
- Hynek Schlawack
- Ivan Katanić
- Jakub Kadlubiec
- Jakub Warczarek
- Jan Hnátek
- Jason Fried
- Jason Friedland
- jgirardet
- Jim Brännlund
- Jimmy Jia
- Joe Antonakakis
- Jon Dufresne
- Jonas Obrist
- Jonty Wareing
- Jose Nazario
- Joseph Larson
- Josh Bode
- Josh Holland
- Joshua Cannon
- José Padilla
- Juan Luis Cano Rodríguez
- kaiix
- Katie McLaughlin
- Katrin Leinweber
- Keith Smiley
- Kenyon Ralph
- Kevin Kirsche
- Kyle Hausmann
- Kyle Sunden
- Lawrence Chan
- Linus Groh
- Loren Carvalho
- Luka Sterbic
- LukasDrude
- Mahmoud Hossam
- Mariatta
- Matt VanEseltine
- Matthew Clapp
- Matthew Walster
- Max Smolens
- Michael Aquilina
- Michael Flaxman
- Michael J. Sullivan
- Michael McClimon
- Miguel Gaiowski
- Mike
- mikehoyio
- Min ho Kim
- Miroslav Shubernetskiy
- MomIsBestFriend
- Nathan Goldbaum
- Nathan Hunt
- Neraste
- Nikolaus Waxweiler
- Ofek Lev
- Osaetin Daniel
- otstrel
- Pablo Galindo
- Paul Ganssle
- Paul Meinhardt
- Peter Bengtsson
- Peter Grayson
- Peter Stensmyr
- pmacosta
- Quentin Pradet
- Ralf Schmitt
- Ramón Valles
- Richard Fearn
- Richard Si
- Rishikesh Jha
- Rupert Bedford
- Russell Davis
- Rémi Verschelde
- Sami Salonen
- Samuel Cormier-Iijima
- Sanket Dasgupta
- Sergi
- Scott Stevenson
- Shantanu
- shaoran
- Shinya Fujino
- springstan
- Stavros Korokithakis
- Stephen Rosen
- Steven M. Vascellaro
- Sunil Kapil
- Sébastien Eustace
- Tal Amuyal
- Terrance
- Thom Lu
- Thomas Grainger
- Tim Gates
- Tim Swast
- Timo
- Toby Fleming
- Tom Christie
- Tony Narlock
- Tsuyoshi Hombashi
- Tushar Chandra
- Tzu-ping Chung
- Utsav Shah
- utsav-dbx
- vezeli
- Ville Skyttä
- Vishwas B Sharma
- Vlad Emelianov
- williamfzc
- wouter bolsterlee
- Yazdan
- Yngve Høiseth
- Yurii Karabas
- Zac Hatfield-Dodds
Change Log
21.4b2
Black
-
Fix crash if the user configuration directory is inaccessible. (#2158)
-
Clarify circumstances in which Black may change the AST (#2159)
Packaging
- Install
primer.json
(used byblack-primer
by default) with black. (#2154)
21.4b1
Black
-
Fix crash on docstrings ending with "\ ". (#2142)
-
Fix crash when atypical whitespace is cleaned out of dostrings (#2120)
-
Reflect the
--skip-magic-trailing-comma
and--experimental-string-processing
flags in the name of the cache file. Without this fix, changes in these flags would not take effect if the cache had already been populated. (#2131) -
Don't remove necessary parentheses from assignment expression containing assert / return statements. (#2143)
Packaging
- Bump pathspec to >= 0.8.1 to solve invalid .gitignore exclusion handling
21.4b0
Black
-
Fixed a rare but annoying formatting instability created by the combination of optional trailing commas inserted by
Black
and optional parentheses looking at pre-existing "magic" trailing commas. This fixes issue #1629 and all of its many many duplicates. (#2126) -
Black
now processes one-line docstrings by stripping leading and trailing spaces, and adding a padding space when needed to break up """". (#1740) -
Black
now cleans up leading non-breaking spaces in comments (#2092) -
Black
now respects--skip-string-normalization
when normalizing multiline docstring quotes (#1637) -
Black
no longer removes all empty lines between non-function code and decorators when formatting typing stubs. NowBlack
enforces a single empty line. (#1646) -
Black
no longer adds an incorrect space after a parenthesized assignment expression in if/while statements (#1655) -
Added
--skip-magic-trailing-comma
/-C
to avoid using trailing commas as a reason to split lines (#1824) -
fixed a crash when PWD=/ on POSIX (#1631)
-
fixed "I/O operation on closed file" when using --diff (#1664)
-
Prevent coloured diff output being interleaved with multiple files (#1673)
-
Added support for PEP 614 relaxed decorator syntax on python 3.9 (#1711)
-
Added parsing support for unparenthesized tuples and yield expressions in annotated assignments (#1835)
-
added
--extend-exclude
argument (PR #2005) -
speed up caching by avoiding pathlib (#1950)
-
--diff
correctly indicates when a file doesn't end in a newline (#1662) -
Added
--stdin-filename
argument to allow stdin to respect--force-exclude
rules (#1780) -
Lines ending with
fmt: skip
will now be not formatted (#1800) -
PR #2053: Black no longer relies on typed-ast for Python 3.8 and higher
-
PR #2053: Python 2 support is now optional, install with
python3 -m pip install black[python2]
to maintain support. -
Exclude
venv
directory by default (#1683) -
Fixed "Black produced code that is not equivalent to the source" when formatting Python 2 docstrings (#2037)
Packaging
- Self-contained native Black binaries are now provided for releases via GitHub Releases (#1743)
20.8b1
Packaging
- explicitly depend on Click 7.1.2 or newer as
Black
no longer works with versions older than 7.0
20.8b0
Black
-
re-implemented support for explicit trailing commas: now it works consistently within any bracket pair, including nested structures (#1288 and duplicates)
-
Black
now reindents docstrings when reindenting code around it (#1053) -
Black
now shows colored diffs (#1266) -
Black
is now packaged using 'py3' tagged wheels (#1388) -
Black
now supports Python 3.8 code, e.g. star expressions in return statements (#1121) -
Black
no longer normalizes capital R-string prefixes as those have a community-accepted meaning (#1244) -
Black
now uses exit code 2 when specified configuration file doesn't exit (#1361) -
Black
now works on AWS Lambda (#1141) -
added
--force-exclude
argument (#1032) -
removed deprecated
--py36
option (#1236) -
fixed
--diff
output when EOF is encountered (#526) -
fixed
# fmt: off
handling around decorators (#560) -
fixed unstable formatting with some
# type: ignore
comments (#1113) -
fixed invalid removal on organizing brackets followed by indexing (#1575)
-
introduced
black-primer
, a CI tool that allows us to run regression tests against existing open source users of Black (#1402) -
introduced property-based fuzzing to our test suite based on Hypothesis and Hypothersmith (#1566)
-
implemented experimental and disabled by default long string rewrapping (#1132), hidden under a
--experimental-string-processing
flag while it's being worked on; this is an undocumented and unsupported feature, you lose Internet points for depending on it (#1609)
Vim plugin
- prefer virtualenv packages over global packages (#1383)
19.10b0
-
added support for PEP 572 assignment expressions (#711)
-
added support for PEP 570 positional-only arguments (#943)
-
added support for async generators (#593)
-
added support for pre-splitting collections by putting an explicit trailing comma inside (#826)
-
added
black -c
as a way to format code passed from the command line (#761) -
--safe now works with Python 2 code (#840)
-
fixed grammar selection for Python 2-specific code (#765)
-
fixed feature detection for trailing commas in function definitions and call sites (#763)
-
# fmt: off
/# fmt: on
comment pairs placed multiple times within the same block of code now behave correctly (#1005) -
Black no longer crashes on Windows machines with more than 61 cores (#838)
-
Black no longer crashes on standalone comments prepended with a backslash (#767)
-
Black no longer crashes on
from
...import
blocks with comments (#829) -
Black no longer crashes on Python 3.7 on some platform configurations (#494)
-
Black no longer fails on comments in from-imports (#671)
-
Black no longer fails when the file starts with a backslash (#922)
-
Black no longer merges regular comments with type comments (#1027)
-
Black no longer splits long lines that contain type comments (#997)
-
removed unnecessary parentheses around
yield
expressions (#834) -
added parentheses around long tuples in unpacking assignments (#832)
-
added parentheses around complex powers when they are prefixed by a unary operator (#646)
-
fixed bug that led Black format some code with a line length target of 1 (#762)
-
Black no longer introduces quotes in f-string subexpressions on string boundaries (#863)
-
if Black puts parenthesis around a single expression, it moves comments to the wrapped expression instead of after the brackets (#872)
-
blackd
now returns the version of Black in the response headers (#1013) -
blackd
can now output the diff of formats on source code when theX-Diff
header is provided (#969)
19.3b0
-
new option
--target-version
to control which Python versions Black-formatted code should target (#618) -
deprecated
--py36
(use--target-version=py36
instead) (#724) -
Black no longer normalizes numeric literals to include
_
separators (#696) -
long
del
statements are now split into multiple lines (#698) -
type comments are no longer mangled in function signatures
-
improved performance of formatting deeply nested data structures (#509)
-
Black now properly formats multiple files in parallel on Windows (#632)
-
Black now creates cache files atomically which allows it to be used in parallel pipelines (like
xargs -P8
) (#673) -
Black now correctly indents comments in files that were previously formatted with tabs (#262)
-
blackd
now supports CORS (#622)
18.9b0
-
numeric literals are now formatted by Black (#452, #461, #464, #469):
-
numeric literals are normalized to include
_
separators on Python 3.6+ code -
added
--skip-numeric-underscore-normalization
to disable the above behavior and leave numeric underscores as they were in the input -
code with
_
in numeric literals is recognized as Python 3.6+ -
most letters in numeric literals are lowercased (e.g., in
1e10
,0x01
) -
hexadecimal digits are always uppercased (e.g.
0xBADC0DE
)
-
-
added
blackd
, see its documentation for more info (#349) -
adjacent string literals are now correctly split into multiple lines (#463)
-
trailing comma is now added to single imports that don't fit on a line (#250)
-
cache is now populated when
--check
is successful for a file which speeds up consecutive checks of properly formatted unmodified files (#448) -
whitespace at the beginning of the file is now removed (#399)
-
fixed mangling pweave and Spyder IDE special comments (#532)
-
fixed unstable formatting when unpacking big tuples (#267)
-
fixed parsing of
__future__
imports with renames (#389) -
fixed scope of
# fmt: off
when directly precedingyield
and other nodes (#385) -
fixed formatting of lambda expressions with default arguments (#468)
-
fixed
async for
statements: Black no longer breaks them into separate lines (#372) -
note: the Vim plugin stopped registering
,=
as a default chord as it turned out to be a bad idea (#415)
18.6b4
- hotfix: don't freeze when multiple comments directly precede
# fmt: off
(#371)
18.6b3
-
typing stub files (
.pyi
) now have blank lines added after constants (#340) -
# fmt: off
and# fmt: on
are now much more dependable:-
they now work also within bracket pairs (#329)
-
they now correctly work across function/class boundaries (#335)
-
they now work when an indentation block starts with empty lines or misaligned comments (#334)
-
-
made Click not fail on invalid environments; note that Click is right but the likelihood we'll need to access non-ASCII file paths when dealing with Python source code is low (#277)
-
fixed improper formatting of f-strings with quotes inside interpolated expressions (#322)
-
fixed unnecessary slowdown when long list literals where found in a file
-
fixed unnecessary slowdown on AST nodes with very many siblings
-
fixed cannibalizing backslashes during string normalization
-
fixed a crash due to symbolic links pointing outside of the project directory (#338)
18.6b2
-
added
--config
(#65) -
added
-h
equivalent to--help
(#316) -
fixed improper unmodified file caching when
-S
was used -
fixed extra space in string unpacking (#305)
-
fixed formatting of empty triple quoted strings (#313)
-
fixed unnecessary slowdown in comment placement calculation on lines without comments
18.6b1
-
hotfix: don't output human-facing information on stdout (#299)
-
hotfix: don't output cake emoji on non-zero return code (#300)
18.6b0
-
added
--include
and--exclude
(#270) -
added
--skip-string-normalization
(#118) -
added
--verbose
(#283) -
the header output in
--diff
now actually conforms to the unified diff spec -
fixed long trivial assignments being wrapped in unnecessary parentheses (#273)
-
fixed unnecessary parentheses when a line contained multiline strings (#232)
-
fixed stdin handling not working correctly if an old version of Click was used (#276)
-
Black now preserves line endings when formatting a file in place (#258)
18.5b1
-
added
--pyi
(#249) -
added
--py36
(#249) -
Python grammar pickle caches are stored with the formatting caches, making Black work in environments where site-packages is not user-writable (#192)
-
Black now enforces a PEP 257 empty line after a class-level docstring (and/or fields) and the first method
-
fixed invalid code produced when standalone comments were present in a trailer that was omitted from line splitting on a large expression (#237)
-
fixed optional parentheses being removed within
# fmt: off
sections (#224) -
fixed invalid code produced when stars in very long imports were incorrectly wrapped in optional parentheses (#234)
-
fixed unstable formatting when inline comments were moved around in a trailer that was omitted from line splitting on a large expression (#238)
-
fixed extra empty line between a class declaration and the first method if no class docstring or fields are present (#219)
-
fixed extra empty line between a function signature and an inner function or inner class (#196)
18.5b0
-
call chains are now formatted according to the fluent interfaces style (#67)
-
data structure literals (tuples, lists, dictionaries, and sets) are now also always exploded like imports when they don't fit in a single line (#152)
-
slices are now formatted according to PEP 8 (#178)
-
parentheses are now also managed automatically on the right-hand side of assignments and return statements (#140)
-
math operators now use their respective priorities for delimiting multiline expressions (#148)
-
optional parentheses are now omitted on expressions that start or end with a bracket and only contain a single operator (#177)
-
empty parentheses in a class definition are now removed (#145, #180)
-
string prefixes are now standardized to lowercase and
u
is removed on Python 3.6+ only code and Python 2.7+ code with theunicode_literals
future import (#188, #198, #199) -
typing stub files (
.pyi
) are now formatted in a style that is consistent with PEP 484 (#207, #210) -
progress when reformatting many files is now reported incrementally
-
fixed trailers (content with brackets) being unnecessarily exploded into their own lines after a dedented closing bracket (#119)
-
fixed an invalid trailing comma sometimes left in imports (#185)
-
fixed non-deterministic formatting when multiple pairs of removable parentheses were used (#183)
-
fixed multiline strings being unnecessarily wrapped in optional parentheses in long assignments (#215)
-
fixed not splitting long from-imports with only a single name
-
fixed Python 3.6+ file discovery by also looking at function calls with unpacking. This fixed non-deterministic formatting if trailing commas where used both in function signatures with stars and function calls with stars but the former would be reformatted to a single line.
-
fixed crash on dealing with optional parentheses (#193)
-
fixed "is", "is not", "in", and "not in" not considered operators for splitting purposes
-
fixed crash when dead symlinks where encountered
18.4a4
- don't populate the cache on
--check
(#175)
18.4a3
-
added a "cache"; files already reformatted that haven't changed on disk won't be reformatted again (#109)
-
--check
and--diff
are no longer mutually exclusive (#149) -
generalized star expression handling, including double stars; this fixes multiplication making expressions "unsafe" for trailing commas (#132)
-
Black no longer enforces putting empty lines behind control flow statements (#90)
-
Black now splits imports like "Mode 3 + trailing comma" of isort (#127)
-
fixed comment indentation when a standalone comment closes a block (#16, #32)
-
fixed standalone comments receiving extra empty lines if immediately preceding a class, def, or decorator (#56, #154)
-
fixed
--diff
not showing entire path (#130) -
fixed parsing of complex expressions after star and double stars in function calls (#2)
-
fixed invalid splitting on comma in lambda arguments (#133)
-
fixed missing splits of ternary expressions (#141)
18.4a2
-
fixed parsing of unaligned standalone comments (#99, #112)
-
fixed placement of dictionary unpacking inside dictionary literals (#111)
-
Vim plugin now works on Windows, too
-
fixed unstable formatting when encountering unnecessarily escaped quotes in a string (#120)
18.4a1
-
added
--quiet
(#78) -
added automatic parentheses management (#4)
-
added pre-commit integration (#103, #104)
-
fixed reporting on
--check
with multiple files (#101, #102) -
fixed removing backslash escapes from raw strings (#100, #105)
18.4a0
-
added
--diff
(#87) -
add line breaks before all delimiters, except in cases like commas, to better comply with PEP 8 (#73)
-
standardize string literals to use double quotes (almost) everywhere (#75)
-
fixed handling of standalone comments within nested bracketed expressions; Black will no longer produce super long lines or put all standalone comments at the end of the expression (#22)
-
fixed 18.3a4 regression: don't crash and burn on empty lines with trailing whitespace (#80)
-
fixed 18.3a4 regression:
# yapf: disable
usage as trailing comment would cause Black to not emit the rest of the file (#95) -
when CTRL+C is pressed while formatting many files, Black no longer freaks out with a flurry of asyncio-related exceptions
-
only allow up to two empty lines on module level and only single empty lines within functions (#74)
18.3a4
-
# fmt: off
and# fmt: on
are implemented (#5) -
automatic detection of deprecated Python 2 forms of print statements and exec statements in the formatted file (#49)
-
use proper spaces for complex expressions in default values of typed function arguments (#60)
-
only return exit code 1 when --check is used (#50)
-
don't remove single trailing commas from square bracket indexing (#59)
-
don't omit whitespace if the previous factor leaf wasn't a math operator (#55)
-
omit extra space in kwarg unpacking if it's the first argument (#46)
-
omit extra space in Sphinx auto-attribute comments (#68)
18.3a3
-
don't remove single empty lines outside of bracketed expressions (#19)
-
added ability to pipe formatting from stdin to stdin (#25)
-
restored ability to format code with legacy usage of
async
as a name (#20, #42) -
even better handling of numpy-style array indexing (#33, again)
18.3a2
-
changed positioning of binary operators to occur at beginning of lines instead of at the end, following a recent change to PEP 8 (#21)
-
ignore empty bracket pairs while splitting. This avoids very weirdly looking formattings (#34, #35)
-
remove a trailing comma if there is a single argument to a call
-
if top level functions were separated by a comment, don't put four empty lines after the upper function
-
fixed unstable formatting of newlines with imports
-
fixed unintentional folding of post scriptum standalone comments into last statement if it was a simple statement (#18, #28)
-
fixed missing space in numpy-style array indexing (#33)
-
fixed spurious space after star-based unary expressions (#31)
18.3a1
-
added
--check
-
only put trailing commas in function signatures and calls if it's safe to do so. If the file is Python 3.6+ it's always safe, otherwise only safe if there are no
*args
or**kwargs
used in the signature or call. (#8) -
fixed invalid spacing of dots in relative imports (#6, #13)
-
fixed invalid splitting after comma on unpacked variables in for-loops (#23)
-
fixed spurious space in parenthesized set expressions (#7)
-
fixed spurious space after opening parentheses and in default arguments (#14, #17)
-
fixed spurious space after unary operators when the operand was a complex expression (#15)
18.3a0
-
first published version, Happy 🍰 Day 2018!
-
alpha quality
-
date-versioned (see: https://calver.org/)
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