All patches and comments are welcome. Please squash your changes to logical
commits before using git-format-patch and git-send-email to
patches@git.madduck.net.
If you'd read over the Git project's submission guidelines and adhered to them,
I'd be especially grateful.
1 ![Black Logo](https://raw.githubusercontent.com/ambv/black/master/docs/_static/logo2-readme.png)
2 <h2 align="center">The Uncompromising Code Formatter</h2>
5 <a href="https://travis-ci.org/ambv/black"><img alt="Build Status" src="https://travis-ci.org/ambv/black.svg?branch=master"></a>
6 <a href="http://black.readthedocs.io/en/stable/?badge=stable"><img alt="Documentation Status" src="http://readthedocs.org/projects/black/badge/?version=stable"></a>
7 <a href="https://coveralls.io/github/ambv/black?branch=master"><img alt="Coverage Status" src="https://coveralls.io/repos/github/ambv/black/badge.svg?branch=master"></a>
8 <a href="https://github.com/ambv/black/blob/master/LICENSE"><img alt="License: MIT" src="http://black.readthedocs.io/en/stable/_static/license.svg"></a>
9 <a href="https://pypi.python.org/pypi/black"><img alt="PyPI" src="http://black.readthedocs.io/en/stable/_static/pypi.svg"></a>
10 <a href="https://github.com/ambv/black"><img alt="Code style: black" src="https://img.shields.io/badge/code%20style-black-000000.svg"></a>
13 > “Any color you like.”
16 *Black* is the uncompromising Python code formatter. By using it, you
17 agree to cede control over minutiae of hand-formatting. In return,
18 *Black* gives you speed, determinism, and freedom from `pycodestyle`
19 nagging about formatting. You will save time and mental energy for
20 more important matters.
22 Blackened code looks the same regardless of the project you're reading.
23 Formatting becomes transparent after a while and you can focus on the
26 *Black* makes code review faster by producing the smallest diffs
30 ## Installation and Usage
34 *Black* can be installed by running `pip install black`. It requires
35 Python 3.6.0+ to run but you can reformat Python 2 code with it, too.
40 To get started right away with sensible defaults:
43 black {source_file_or_directory}
46 ### Command line options
48 Black doesn't provide many options. You can list them by running
52 black [OPTIONS] [SRC]...
55 -l, --line-length INTEGER Where to wrap around. [default: 88]
56 --check Don't write the files back, just return the
57 status. Return code 0 means nothing would
58 change. Return code 1 means some files would be
59 reformatted. Return code 123 means there was an
61 --diff Don't write the files back, just output a diff
62 for each file on stdout.
63 --fast / --safe If --fast given, skip temporary sanity checks.
65 -q, --quiet Don't emit non-error messages to stderr. Errors
66 are still emitted, silence those with
68 --version Show the version and exit.
69 --help Show this message and exit.
72 *Black* is a well-behaved Unix-style command-line tool:
73 * it does nothing if no sources are passed to it;
74 * it will read from standard input and write to standard output if `-`
75 is used as the filename;
76 * it only outputs messages to users on standard error;
77 * exits with code 0 unless an internal error occurred (or `--check` was
81 ### NOTE: This is an early pre-release
83 *Black* can already successfully format itself and the standard library.
84 It also sports a decent test suite. However, it is still very new.
85 Things will probably be wonky for a while. This is made explicit by the
86 "Alpha" trove classifier, as well as by the "a" in the version number.
87 What this means for you is that **until the formatter becomes stable,
88 you should expect some formatting to change in the future**.
90 Also, as a temporary safety measure, *Black* will check that the
91 reformatted code still produces a valid AST that is equivalent to the
92 original. This slows it down. If you're feeling confident, use
96 ## The *Black* code style
98 *Black* reformats entire files in place. It is not configurable. It
99 doesn't take previous formatting into account. It doesn't reformat
100 blocks that start with `# fmt: off` and end with `# fmt: on`. It also
101 recognizes [YAPF](https://github.com/google/yapf)'s block comments to
102 the same effect, as a courtesy for straddling code.
105 ### How *Black* wraps lines
107 *Black* ignores previous formatting and applies uniform horizontal
108 and vertical whitespace to your code. The rules for horizontal
109 whitespace can be summarized as: do whatever makes `pycodestyle` happy.
110 The coding style used by *Black* can be viewed as a strict subset of
113 As for vertical whitespace, *Black* tries to render one full expression
114 or simple statement per line. If this fits the allotted line length,
129 If not, *Black* will look at the contents of the first outer matching
130 brackets and put that in a separate indented line.
134 l = [[n for n in list_bosses()], [n for n in list_employees()]]
139 [n for n in list_bosses()], [n for n in list_employees()]
143 If that still doesn't fit the bill, it will decompose the internal
144 expression further using the same rule, indenting matching brackets
145 every time. If the contents of the matching brackets pair are
146 comma-separated (like an argument list, or a dict literal, and so on)
147 then *Black* will first try to keep them on the same line with the
148 matching brackets. If that doesn't work, it will put all of them in
153 def very_important_function(template: str, *variables, file: os.PathLike, debug: bool = False):
154 """Applies `variables` to the `template` and writes to `file`."""
155 with open(file, 'w') as f:
160 def very_important_function(
166 """Applies `variables` to the `template` and writes to `file`."""
167 with open(file, "w") as f:
171 You might have noticed that closing brackets are always dedented and
172 that a trailing comma is always added. Such formatting produces smaller
173 diffs; when you add or remove an element, it's always just one line.
174 Also, having the closing bracket dedented provides a clear delimiter
175 between two distinct sections of the code that otherwise share the same
176 indentation level (like the arguments list and the docstring in the
179 If a line of "from" imports cannot fit in the allotted length, it's always split
180 into one per line. Imports tend to change often and this minimizes diffs, as well
181 as enables readers of code to easily find which commit introduced a particular
182 import. This exception also makes *Black* compatible with
183 [isort](https://pypi.org/p/isort/). Use `multi_line_output=3`,
184 `include_trailing_comma=True`, `force_grid_wrap=0`, and `line_length=88` in your
190 You probably noticed the peculiar default line length. *Black* defaults
191 to 88 characters per line, which happens to be 10% over 80. This number
192 was found to produce significantly shorter files than sticking with 80
193 (the most popular), or even 79 (used by the standard library). In
194 general, [90-ish seems like the wise choice](https://youtu.be/wf-BqAjZb8M?t=260).
196 If you're paid by the line of code you write, you can pass
197 `--line-length` with a lower number. *Black* will try to respect that.
198 However, sometimes it won't be able to without breaking other rules. In
199 those rare cases, auto-formatted code will exceed your allotted limit.
201 You can also increase it, but remember that people with sight disabilities
202 find it harder to work with line lengths exceeding 100 characters.
203 It also adversely affects side-by-side diff review on typical screen
204 resolutions. Long lines also make it harder to present code neatly
205 in documentation or talk slides.
207 If you're using Flake8, you can bump `max-line-length` to 88 and forget
208 about it. Alternatively, use [Bugbear](https://github.com/PyCQA/flake8-bugbear)'s
209 B950 warning instead of E501 and keep the max line length at 80 which
210 you are probably already using. You'd do it like this:
215 select = C,E,F,W,B,B950
219 You'll find *Black*'s own .flake8 config file is configured like this.
220 If you're curious about the reasoning behind B950, Bugbear's documentation
221 explains it. The tl;dr is "it's like highway speed limits, we won't
222 bother you if you overdo it by a few km/h".
227 *Black* avoids spurious vertical whitespace. This is in the spirit of
228 PEP 8 which says that in-function vertical whitespace should only be
231 *Black* will allow single empty lines inside functions, and single and
232 double empty lines on module level left by the original editors, except
233 when they're within parenthesized expressions. Since such expressions
234 are always reformatted to fit minimal space, this whitespace is lost.
236 It will also insert proper spacing before and after function definitions.
237 It's one line before and after inner functions and two lines before and
238 after module-level functions. *Black* will not put empty lines between
239 function/class definitions and standalone comments that immediately precede
240 the given function/class.
245 *Black* will add trailing commas to expressions that are split
246 by comma where each element is on its own line. This includes function
249 Unnecessary trailing commas are removed if an expression fits in one
250 line. This makes it 1% more likely that your line won't exceed the
251 allotted line length limit. Moreover, in this scenario, if you added
252 another argument to your call, you'd probably fit it in the same line
253 anyway. That doesn't make diffs any larger.
255 One exception to removing trailing commas is tuple expressions with
256 just one element. In this case *Black* won't touch the single trailing
257 comma as this would unexpectedly change the underlying data type. Note
258 that this is also the case when commas are used while indexing. This is
259 a tuple in disguise: ```numpy_array[3, ]```.
261 One exception to adding trailing commas is function signatures
262 containing `*`, `*args`, or `**kwargs`. In this case a trailing comma
263 is only safe to use on Python 3.6. *Black* will detect if your file is
264 already 3.6+ only and use trailing commas in this situation. If you
265 wonder how it knows, it looks for f-strings and existing use of trailing
266 commas in function signatures that have stars in them. In other words,
267 if you'd like a trailing comma in this situation and *Black* didn't
268 recognize it was safe to do so, put it there manually and *Black* will
273 *Black* prefers double quotes (`"` and `"""`) over single quotes (`'`
274 and `'''`). It will replace the latter with the former as long as it
275 does not result in more backslash escapes than before.
277 *Black* also standardizes string prefixes, making them always lowercase.
278 On top of that, if your code is already Python 3.6+ only or it's using
279 the `unicode_literals` future import, *Black* will remove `u` from the
280 string prefix as it is meaningless in those scenarios.
282 The main reason to standardize on a single form of quotes is aesthetics.
283 Having one kind of quotes everywhere reduces reader distraction.
284 It will also enable a future version of *Black* to merge consecutive
285 string literals that ended up on the same line (see
286 [#26](https://github.com/ambv/black/issues/26) for details).
288 Why settle on double quotes? They anticipate apostrophes in English
289 text. They match the docstring standard described in PEP 257. An
290 empty string in double quotes (`""`) is impossible to confuse with
291 a one double-quote regardless of fonts and syntax highlighting used.
292 On top of this, double quotes for strings are consistent with C which
293 Python interacts a lot with.
295 On certain keyboard layouts like US English, typing single quotes is
296 a bit easier than double quotes. The latter requires use of the Shift
297 key. My recommendation here is to keep using whatever is faster to type
298 and let *Black* handle the transformation.
300 ### Line Breaks & Binary Operators
302 *Black* will break a line before a binary operator when splitting a block
303 of code over multiple lines. This is so that *Black* is compliant with the
304 recent changes in the [PEP 8](https://www.python.org/dev/peps/pep-0008/#should-a-line-break-before-or-after-a-binary-operator)
305 style guide, which emphasizes that this approach improves readability.
307 This behaviour may raise ``W503 line break before binary operator`` warnings in
308 style guide enforcement tools like Flake8. Since ``W503`` is not PEP 8 compliant,
309 you should tell Flake8 to ignore these warnings.
313 PEP 8 [recommends](https://www.python.org/dev/peps/pep-0008/#whitespace-in-expressions-and-statements)
314 to treat ``:`` in slices as a binary operator with the lowest priority, and to
315 leave an equal amount of space on either side, except if a parameter is omitted
316 (e.g. ``ham[1 + 1 :]``). It also states that for extended slices, both ``:``
317 operators have to have the same amount of spacing, except if a parameter is
318 omitted (``ham[1 + 1 ::]``). *Black* enforces these rules consistently.
320 This behaviour may raise ``E203 whitespace before ':'`` warnings in style guide
321 enforcement tools like Flake8. Since ``E203`` is not PEP 8 compliant, you should
322 tell Flake8 to ignore these warnings.
326 Some parentheses are optional in the Python grammar. Any expression can
327 be wrapped in a pair of parentheses to form an atom. There are a few
332 - `for (...) in (...):`
333 - `assert (...), (...)`
334 - `from X import (...)`
337 - `target: type = (...)`
338 - `some, *un, packing = (...)`
339 - `augmented += (...)`
341 In those cases, parentheses are removed when the entire statement fits
342 in one line, or if the inner expression doesn't have any delimiters to
343 further split on. If there is only a single delimiter and the expression
344 starts or ends with a bracket, the parenthesis can also be successfully
345 omitted since the existing bracket pair will organize the expression
346 neatly anyway. Otherwise, the parentheses are added.
348 Please note that *Black* does not add or remove any additional nested
349 parentheses that you might want to have for clarity or further
350 code organization. For example those parentheses are not going to be
353 return not (this or that)
354 decision = (maybe.this() and values > 0) or (maybe.that() and values < 0)
359 Some popular APIs, like ORMs, use call chaining. This API style is known
360 as a [fluent interface](https://en.wikipedia.org/wiki/Fluent_interface).
361 *Black* formats those treating dots that follow a call or an indexing
362 operation like a very low priority delimiter. It's easier to show the
363 behavior than to explain it. Look at the example:
365 def example(session):
367 session.query(models.Customer.id)
369 models.Customer.account_id == account_id,
370 models.Customer.email == email_address,
372 .order_by(models.Customer.id.asc())
377 ### Typing stub files
379 PEP 484 describes the syntax for type hints in Python. One of the
380 use cases for typing is providing type annotations for modules which
381 cannot contain them directly (they might be written in C, or they might
382 be third-party, or their implementation may be overly dynamic, and so on).
384 To solve this, [stub files with the `.pyi` file
385 extension](https://www.python.org/dev/peps/pep-0484/#stub-files) can be
386 used to describe typing information for an external module. Those stub
387 files omit the implementation of classes and functions they
388 describe, instead they only contain the structure of the file (listing
389 globals, functions, and classes with their members). The recommended
390 code style for those files is more terse than PEP 8:
392 * prefer `...` on the same line as the class/function signature;
393 * avoid vertical whitespace between consecutive module-level functions,
394 names, or methods and fields within a single class;
395 * use a single blank line between top-level class definitions, or none
396 if the classes are very small.
398 *Black* enforces the above rules. There are additional guidelines for
399 formatting `.pyi` file that are not enforced yet but might be in
400 a future version of the formatter:
402 * all function bodies should be empty (contain `...` instead of the body);
403 * do not use docstrings;
404 * prefer `...` over `pass`;
405 * for arguments with a default, use `...` instead of the actual default;
406 * avoid using string literals in type annotations, stub files support
407 forward references natively (like Python 3.7 code with `from __future__
408 import annotations`);
409 * use variable annotations instead of type comments, even for stubs that
410 target older versions of Python;
411 * for arguments that default to `None`, use `Optional[]` explicitly;
412 * use `float` instead of `Union[int, float]`.
415 ## Editor integration
419 Use [proofit404/blacken](https://github.com/proofit404/blacken).
428 2. Locate your `black` installation folder.
430 On MacOS / Linux / BSD:
433 /usr/local/bin/black # possible location
438 %LocalAppData%\Programs\Python\Python36-32\Scripts\black.exe # possible location
440 3. Open External tools in PyCharm with `File -> Settings -> Tools -> External Tools`.
442 4. Click the + icon to add a new external tool with the following values:
444 - Description: Black is the uncompromising Python code formatter.
445 - Program: <install_location_from_step_2>
446 - Arguments: $FilePath$
448 5. Format the currently opened file by selecting `Tools -> External Tools -> black`.
449 - Alternatively, you can set a keyboard shortcut by navigating to `Preferences -> Keymap`.
454 Commands and shortcuts:
456 * `,=` or `:Black` to format the entire file (ranges not supported);
457 * `:BlackUpgrade` to upgrade *Black* inside the virtualenv;
458 * `:BlackVersion` to get the current version of *Black* inside the
462 * `g:black_fast` (defaults to `0`)
463 * `g:black_linelength` (defaults to `88`)
464 * `g:black_virtualenv` (defaults to `~/.vim/black`)
466 To install with [vim-plug](https://github.com/junegunn/vim-plug):
472 or with [Vundle](https://github.com/VundleVim/Vundle.vim):
478 or you can copy the plugin from [plugin/black.vim](https://github.com/ambv/black/tree/master/plugin/black.vim).
479 Let me know if this requires any changes to work with Vim 8's builtin
480 `packadd`, or Pathogen, and so on.
482 This plugin **requires Vim 7.0+ built with Python 3.6+ support**. It
483 needs Python 3.6 to be able to run *Black* inside the Vim process which
484 is much faster than calling an external command.
486 On first run, the plugin creates its own virtualenv using the right
487 Python version and automatically installs *Black*. You can upgrade it later
488 by calling `:BlackUpgrade` and restarting Vim.
490 If you need to do anything special to make your virtualenv work and
491 install *Black* (for example you want to run a version from master),
492 create a virtualenv manually and point `g:black_virtualenv` to it.
493 The plugin will use it.
495 **How to get Vim with Python 3.6?**
496 On Ubuntu 17.10 Vim comes with Python 3.6 by default.
497 On macOS with HomeBrew run: `brew install vim --with-python3`.
498 When building Vim from source, use:
499 `./configure --enable-python3interp=yes`. There's many guides online how
503 ### Visual Studio Code
505 Use [joslarson.black-vscode](https://marketplace.visualstudio.com/items?itemName=joslarson.black-vscode).
509 Use [sublack plugin](https://github.com/jgirardet/sublack).
511 ### IPython Notebook Magic
513 Use [blackcellmagic](https://github.com/csurfer/blackcellmagic).
517 Atom/Nuclide integration is planned by the author, others will
518 require external contributions.
520 Patches welcome! ✨ 🍰 ✨
522 Any tool that can pipe code through *Black* using its stdio mode (just
523 [use `-` as the file name](http://www.tldp.org/LDP/abs/html/special-chars.html#DASHREF2)).
524 The formatted code will be returned on stdout (unless `--check` was
525 passed). *Black* will still emit messages on stderr but that shouldn't
526 affect your use case.
528 This can be used for example with PyCharm's [File Watchers](https://www.jetbrains.com/help/pycharm/file-watchers.html).
531 ## Version control integration
533 Use [pre-commit](https://pre-commit.com/). Once you [have it
534 installed](https://pre-commit.com/#install), add this to the
535 `.pre-commit-config.yaml` in your repository:
538 - repo: https://github.com/ambv/black
542 args: [--line-length=88, --safe]
543 python_version: python3.6
545 Then run `pre-commit install` and you're ready to go.
547 `args` in the above config is optional but shows you how you can change
548 the line length if you really need to. If you're already using Python
549 3.7, switch the `python_version` accordingly. Finally, `stable` is a tag
550 that is pinned to the latest release on PyPI. If you'd rather run on
551 master, this is also an option.
554 ## Ignoring non-modified files
556 *Black* remembers files it already formatted, unless the `--diff` flag is used or
557 code is passed via standard input. This information is stored per-user. The exact
558 location of the file depends on the black version and the system on which black
559 is run. The file is non-portable. The standard location on common operating systems
562 * Windows: `C:\\Users\<username>\AppData\Local\black\black\Cache\<version>\cache.<line-length>.pickle`
563 * macOS: `/Users/<username>/Library/Caches/black/<version>/cache.<line-length>.pickle`
564 * Linux: `/home/<username>/.cache/black/<version>/cache.<line-length>.pickle`
569 **Dusty Phillips**, [writer](https://smile.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=dusty+phillips):
571 > Black is opinionated so you don't have to be.
573 **Hynek Schlawack**, [creator of `attrs`](http://www.attrs.org/), core
574 developer of Twisted and CPython:
576 > An auto-formatter that doesn't suck is all I want for Xmas!
578 **Carl Meyer**, [Django](https://www.djangoproject.com/) core developer:
580 > At least the name is good.
582 **Kenneth Reitz**, creator of [`requests`](http://python-requests.org/)
583 and [`pipenv`](https://docs.pipenv.org/):
585 > This vastly improves the formatting of our code. Thanks a ton!
590 Use the badge in your project's README.md:
593 [![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/ambv/black)
596 Looks like this: [![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/ambv/black)
604 ## Contributing to Black
606 In terms of inspiration, *Black* is about as configurable as *gofmt*.
609 Bug reports and fixes are always welcome! However, before you suggest a
610 new feature or configuration knob, ask yourself why you want it. If it
611 enables better integration with some workflow, fixes an inconsistency,
612 speeds things up, and so on - go for it! On the other hand, if your
613 answer is "because I don't like a particular formatting" then you're not
614 ready to embrace *Black* yet. Such changes are unlikely to get accepted.
615 You can still try but prepare to be disappointed.
617 More details can be found in [CONTRIBUTING](CONTRIBUTING.md).
622 ### 18.5a0 (unreleased)
624 * call chains are now formatted according to the [fluent interfaces](https://en.wikipedia.org/wiki/Fluent_interface) style (#67)
626 * slices are now formatted according to PEP 8 (#178)
628 * parentheses are now also managed automatically on the right-hand side
629 of assignments and return statements (#140)
631 * math operators now use their respective priorities for delimiting multiline
634 * optional parentheses are now omitted on expressions that start or end
635 with a bracket and only contain a single operator (#177)
637 * empty parentheses in a class definition are now removed (#145, #180)
639 * string prefixes are now standardized to lowercase and `u` is removed
640 on Python 3.6+ only code and Python 2.7+ code with the `unicode_literals`
641 future import (#188, #198, #199)
643 * typing stub files (`.pyi`) are now formatted in a style that is consistent
644 with PEP 484 (#207, #210)
646 * progress when reformatting many files is now reported incrementally
648 * fixed trailers (content with brackets) being unnecessarily exploded
649 into their own lines after a dedented closing bracket (#119)
651 * fixed an invalid trailing comma sometimes left in imports (#185)
653 * fixed non-deterministic formatting when multiple pairs of removable parentheses
656 * fixed multiline strings being unnecessarily wrapped in optional
657 parentheses in long assignments (#215)
659 * fixed not splitting long from-imports with only a single name
661 * fixed Python 3.6+ file discovery by also looking at function calls with
662 unpacking. This fixed non-deterministic formatting if trailing commas
663 where used both in function signatures with stars and function calls
664 with stars but the former would be reformatted to a single line.
666 * fixed crash on dealing with optional parentheses (#193)
668 * fixed "is", "is not", "in", and "not in" not considered operators for
671 * fixed crash when dead symlinks where encountered
676 * don't populate the cache on `--check` (#175)
681 * added a "cache"; files already reformatted that haven't changed on disk
682 won't be reformatted again (#109)
684 * `--check` and `--diff` are no longer mutually exclusive (#149)
686 * generalized star expression handling, including double stars; this
687 fixes multiplication making expressions "unsafe" for trailing commas (#132)
689 * Black no longer enforces putting empty lines behind control flow statements
692 * Black now splits imports like "Mode 3 + trailing comma" of isort (#127)
694 * fixed comment indentation when a standalone comment closes a block (#16, #32)
696 * fixed standalone comments receiving extra empty lines if immediately preceding
697 a class, def, or decorator (#56, #154)
699 * fixed `--diff` not showing entire path (#130)
701 * fixed parsing of complex expressions after star and double stars in
704 * fixed invalid splitting on comma in lambda arguments (#133)
706 * fixed missing splits of ternary expressions (#141)
711 * fixed parsing of unaligned standalone comments (#99, #112)
713 * fixed placement of dictionary unpacking inside dictionary literals (#111)
715 * Vim plugin now works on Windows, too
717 * fixed unstable formatting when encountering unnecessarily escaped quotes
723 * added `--quiet` (#78)
725 * added automatic parentheses management (#4)
727 * added [pre-commit](https://pre-commit.com) integration (#103, #104)
729 * fixed reporting on `--check` with multiple files (#101, #102)
731 * fixed removing backslash escapes from raw strings (#100, #105)
736 * added `--diff` (#87)
738 * add line breaks before all delimiters, except in cases like commas, to
739 better comply with PEP 8 (#73)
741 * standardize string literals to use double quotes (almost) everywhere
744 * fixed handling of standalone comments within nested bracketed
745 expressions; Black will no longer produce super long lines or put all
746 standalone comments at the end of the expression (#22)
748 * fixed 18.3a4 regression: don't crash and burn on empty lines with
749 trailing whitespace (#80)
751 * fixed 18.3a4 regression: `# yapf: disable` usage as trailing comment
752 would cause Black to not emit the rest of the file (#95)
754 * when CTRL+C is pressed while formatting many files, Black no longer
755 freaks out with a flurry of asyncio-related exceptions
757 * only allow up to two empty lines on module level and only single empty
758 lines within functions (#74)
763 * `# fmt: off` and `# fmt: on` are implemented (#5)
765 * automatic detection of deprecated Python 2 forms of print statements
766 and exec statements in the formatted file (#49)
768 * use proper spaces for complex expressions in default values of typed
769 function arguments (#60)
771 * only return exit code 1 when --check is used (#50)
773 * don't remove single trailing commas from square bracket indexing
776 * don't omit whitespace if the previous factor leaf wasn't a math
779 * omit extra space in kwarg unpacking if it's the first argument (#46)
781 * omit extra space in [Sphinx auto-attribute comments](http://www.sphinx-doc.org/en/stable/ext/autodoc.html#directive-autoattribute)
787 * don't remove single empty lines outside of bracketed expressions
790 * added ability to pipe formatting from stdin to stdin (#25)
792 * restored ability to format code with legacy usage of `async` as
795 * even better handling of numpy-style array indexing (#33, again)
800 * changed positioning of binary operators to occur at beginning of lines
801 instead of at the end, following [a recent change to PEP8](https://github.com/python/peps/commit/c59c4376ad233a62ca4b3a6060c81368bd21e85b)
804 * ignore empty bracket pairs while splitting. This avoids very weirdly
805 looking formattings (#34, #35)
807 * remove a trailing comma if there is a single argument to a call
809 * if top level functions were separated by a comment, don't put four
810 empty lines after the upper function
812 * fixed unstable formatting of newlines with imports
814 * fixed unintentional folding of post scriptum standalone comments
815 into last statement if it was a simple statement (#18, #28)
817 * fixed missing space in numpy-style array indexing (#33)
819 * fixed spurious space after star-based unary expressions (#31)
826 * only put trailing commas in function signatures and calls if it's
827 safe to do so. If the file is Python 3.6+ it's always safe, otherwise
828 only safe if there are no `*args` or `**kwargs` used in the signature
831 * fixed invalid spacing of dots in relative imports (#6, #13)
833 * fixed invalid splitting after comma on unpacked variables in for-loops
836 * fixed spurious space in parenthesized set expressions (#7)
838 * fixed spurious space after opening parentheses and in default
841 * fixed spurious space after unary operators when the operand was
842 a complex expression (#15)
847 * first published version, Happy 🍰 Day 2018!
851 * date-versioned (see: https://calver.org/)
856 Glued together by [Łukasz Langa](mailto:lukasz@langa.pl).
858 Maintained with [Carol Willing](mailto:carolcode@willingconsulting.com),
859 [Carl Meyer](mailto:carl@oddbird.net),
860 [Mika Naylor](mailto:mail@autophagy.io), and
861 [Zsolt Dollenstein](mailto:zsol.zsol@gmail.com).
863 Multiple contributions by:
864 * [Anthony Sottile](mailto:asottile@umich.edu)
865 * [Artem Malyshev](mailto:proofit404@gmail.com)
866 * [Christian Heimes](mailto:christian@python.org)
867 * [Daniel M. Capella](mailto:polycitizen@gmail.com)
868 * [Eli Treuherz](mailto:eli.treuherz@cgi.com)
870 * [Ivan Katanić](mailto:ivan.katanic@gmail.com)
871 * [Jelle Zijlstra](mailto:jelle.zijlstra@gmail.com)
872 * [Jonas Obrist](mailto:ojiidotch@gmail.com)
873 * [Miguel Gaiowski](mailto:miggaiowski@gmail.com)
874 * [Osaetin Daniel](mailto:osaetindaniel@gmail.com)
875 * [Sunil Kapil](mailto:snlkapil@gmail.com)
876 * [Vishwas B Sharma](mailto:sharma.vishwas88@gmail.com)