CHANGES.md

Change Log

Unreleased

Highlights

Style

• Fix unstable formatting involving # fmt: skip comments without internal spaces (#2970)

Preview style

• Remove redundant parentheses around awaited objects (#2991)
• Parentheses around return annotations are now managed (#2990)
• Remove unnecessary parentheses from with statements (#2926)

Blackd

Configuration

Documentation

Integrations

Output

• Output python version and implementation as part of --version flag (#2997)

Packaging

• Use tomli instead of tomllib on Python 3.11 builds where tomllib is not available (#2987)

Parser

• PEP 654 syntax (for example, except *ExceptionGroup:) is now supported (#3016)

Performance

22.3.0

Preview style

• Code cell separators #%% are now standardised to # %% (#2919)
• Remove unnecessary parentheses from except statements (#2939)
• Remove unnecessary parentheses from tuple unpacking in for loops (#2945)
• Avoid magic-trailing-comma in single-element subscripts (#2942)

Configuration

• Do not format __pypackages__ directories by default (#2836)
• Add support for specifying stable version with --required-version (#2832).
• Avoid crashing when the user has no homedir (#2814)
• Avoid crashing when md5 is not available (#2905)
• Fix handling of directory junctions on Windows (#2904)

Documentation

• Update pylint config documentation (#2931)

Integrations

• Move test to disable plugin in Vim/Neovim, which speeds up loading (#2896)

Output

• In verbose, mode, log when Black is using user-level config (#2861)

Packaging

• Fix Black to work with Click 8.1.0 (#2966)
• On Python 3.11 and newer, use the standard library's tomllib instead of tomli (#2903)
• black-primer, the deprecated internal devtool, has been removed and copied to a separate repository (#2924)

Parser

• Black can now parse starred expressions in the target of for and async for statements, e.g for item in *items_1, *items_2: pass (#2879).

22.1.0

At long last, Black is no longer a beta product! This is the first non-beta release and the first release covered by our new stability policy.

Highlights

• Remove Python 2 support (#2740)
• Introduce the --preview flag (#2752)

Style

• Deprecate --experimental-string-processing and move the functionality under --preview (#2789)
• For stubs, one blank line between class attributes and methods is now kept if there's at least one pre-existing blank line (#2736)
• Black now normalizes string prefix order (#2297)
• Remove spaces around power operators if both operands are simple (#2726)
• Work around bug that causes unstable formatting in some cases in the presence of the magic trailing comma (#2807)
• Use parentheses for attribute access on decimal float and int literals (#2799)
• Don't add whitespace for attribute access on hexadecimal, binary, octal, and complex literals (#2799)
• Treat blank lines in stubs the same inside top-level if statements (#2820)
• Fix unstable formatting with semicolons and arithmetic expressions (#2817)
• Fix unstable formatting around magic trailing comma (#2572)

Parser

• Fix mapping cases that contain as-expressions, like case {"key": 1 | 2 as password} (#2686)
• Fix cases that contain multiple top-level as-expressions, like case 1 as a, 2 as b (#2716)
• Fix call patterns that contain as-expressions with keyword arguments, like case Foo(bar=baz as quux) (#2749)
• Tuple unpacking on return and yield constructs now implies 3.8+ (#2700)
• Unparenthesized tuples on annotated assignments (e.g values: Tuple[int, ...] = 1, 2, 3) now implies 3.8+ (#2708)
• Fix handling of standalone match() or case() when there is a trailing newline or a comment inside of the parentheses. (#2760)
• from __future__ import annotations statement now implies Python 3.7+ (#2690)

Performance

• Speed-up the new backtracking parser about 4X in general (enabled when --target-version is set to 3.10 and higher). (#2728)
• Black is now compiled with mypyc for an overall 2x speed-up. 64-bit Windows, MacOS, and Linux (not including musl) are supported. (#1009, #2431)

Configuration

• Do not accept bare carriage return line endings in pyproject.toml (#2408)
• Add configuration option (python-cell-magics) to format cells with custom magics in Jupyter Notebooks (#2744)
• Allow setting custom cache directory on all platforms with environment variable BLACK_CACHE_DIR (#2739).
• Enable Python 3.10+ by default, without any extra need to specify --target-version=py310. (#2758)
• Make passing SRC or --code mandatory and mutually exclusive (#2804)

Output

• Improve error message for invalid regular expression (#2678)
• Improve error message when parsing fails during AST safety check by embedding the underlying SyntaxError (#2693)
• No longer color diff headers white as it's unreadable in light themed terminals (#2691)
• Text coloring added in the final statistics (#2712)
• Verbose mode also now describes how a project root was discovered and which paths will be formatted. (#2526)

Packaging

• All upper version bounds on dependencies have been removed (#2718)
• typing-extensions is no longer a required dependency in Python 3.10+ (#2772)
• Set click lower bound to 8.0.0 (#2791)

Integrations

• Update GitHub action to support containerized runs (#2748)

Documentation

• Change protocol in pip installation instructions to https:// (#2761)
• Change HTML theme to Furo primarily for its responsive design and mobile support (#2793)
• Deprecate the black-primer tool (#2809)
• Document Python support policy (#2819)

21.12b0

Black

• Fix determination of f-string expression spans (#2654)
• Fix bad formatting of error messages about EOF in multi-line statements (#2343)
• Functions and classes in blocks now have more consistent surrounding spacing (#2472)

Jupyter Notebook support

• Cell magics are now only processed if they are known Python cell magics. Earlier, all cell magics were tokenized, leading to possible indentation errors e.g. with %%writefile. (#2630)
• Fix assignment to environment variables in Jupyter Notebooks (#2642)

Python 3.10 support

• Point users to using --target-version py310 if we detect 3.10-only syntax (#2668)
• Fix match statements with open sequence subjects, like match a, b: or match a, *b: (#2639) (#2659)
• Fix match/case statements that contain match/case soft keywords multiple times, like match re.match() (#2661)
• Fix case statements with an inline body (#2665)
• Fix styling of starred expressions inside match subject (#2667)
• Fix parser error location on invalid syntax in a match statement (#2649)
• Fix Python 3.10 support on platforms without ProcessPoolExecutor (#2631)
• Improve parsing performance on code that uses match under --target-version py310 up to ~50% (#2670)

Packaging

• Remove dependency on regex (#2644) (#2663)

21.11b1

Black

• Bumped regex version minimum to 2021.4.4 to fix Pattern class usage (#2621)

21.11b0

Black

• Warn about Python 2 deprecation in more cases by improving Python 2 only syntax detection (#2592)
• Add experimental PyPy support (#2559)
• Add partial support for the match statement. As it's experimental, it's only enabled when --target-version py310 is explicitly specified (#2586)
• Add support for parenthesized with (#2586)
• Declare support for Python 3.10 for running Black (#2562)

Integrations

• Fixed vim plugin with Python 3.10 by removing deprecated distutils import (#2610)
• The vim plugin now parses skip_magic_trailing_comma from pyproject.toml (#2613)

21.10b0

Black

• Document stability policy, that will apply for non-beta releases (#2529)
• Add new --workers parameter (#2514)
• Fixed feature detection for positional-only arguments in lambdas (#2532)
• Bumped typed-ast version minimum to 1.4.3 for 3.10 compatibility (#2519)
• Fixed a Python 3.10 compatibility issue where the loop argument was still being passed even though it has been removed (#2580)
• Deprecate Python 2 formatting support (#2523)

Blackd

• Remove dependency on aiohttp-cors (#2500)
• Bump required aiohttp version to 3.7.4 (#2509)

Black-Primer

• Add primer support for --projects (#2555)
• Print primer summary after individual failures (#2570)

Integrations

• Allow to pass target_version in the vim plugin (#1319)
• Install build tools in docker file and use multi-stage build to keep the image size down (#2582)

21.9b0

Packaging

• Fix missing modules in self-contained binaries (#2466)
• Fix missing toml extra used during installation (#2475)

21.8b0

Black

• Add support for formatting Jupyter Notebook files (#2357)
• Move from appdirs dependency to platformdirs (#2375)
• Present a more user-friendly error if .gitignore is invalid (#2414)
• The failsafe for accidentally added backslashes in f-string expressions has been hardened to handle more edge cases during quote normalization (#2437)
• Avoid changing a function return type annotation's type to a tuple by adding a trailing comma (#2384)
• Parsing support has been added for unparenthesized walruses in set literals, set comprehensions, and indices (#2447).
• Pin setuptools-scm build-time dependency version (#2457)
• Exclude typing-extensions version 3.10.0.1 due to it being broken on Python 3.10 (#2460)

Blackd

• Replace sys.exit(-1) with raise ImportError as it plays more nicely with tools that scan installed packages (#2440)

Integrations

• The provided pre-commit hooks no longer specify language_version to avoid overriding default_language_version (#2430)

21.7b0

Black

• Configuration files using TOML features higher than spec v0.5.0 are now supported (#2301)
• Add primer support and test for code piped into black via STDIN (#2315)
• Fix internal error when FORCE_OPTIONAL_PARENTHESES feature is enabled (#2332)
• Accept empty stdin (#2346)
• Provide a more useful error when parsing fails during AST safety checks (#2304)

Docker

• Add new latest_release tag automation to follow latest black release on docker images (#2374)

Integrations

• The vim plugin now searches upwards from the directory containing the current buffer instead of the current working directory for pyproject.toml. (#1871)
• The vim plugin now reads the correct string normalization option in pyproject.toml (#1869)
• The vim plugin no longer crashes Black when there's boolean values in pyproject.toml (#1869)

21.6b0

Black

• Fix failure caused by fmt: skip and indentation (#2281)
• Account for += assignment when deciding whether to split string (#2312)
• Correct max string length calculation when there are string operators (#2292)
• Fixed option usage when using the --code flag (#2259)
• Do not call uvloop.install() when Black is used as a library (#2303)
• Added --required-version option to require a specific version to be running (#2300)
• Fix incorrect custom breakpoint indices when string group contains fake f-strings (#2311)
• Fix regression where R prefixes would be lowercased for docstrings (#2285)
• Fix handling of named escapes (\N{...}) when --experimental-string-processing is used (#2319)

Integrations

• The official Black action now supports choosing what version to use, and supports the major 3 OSes. (#1940)

21.5b2

Black

• A space is no longer inserted into empty docstrings (#2249)
• Fix handling of .gitignore files containing non-ASCII characters on Windows (#2229)
• Respect .gitignore files in all levels, not only root/.gitignore file (apply .gitignore rules like git does) (#2225)
• Restored compatibility with Click 8.0 on Python 3.6 when LANG=C used (#2227)
• Add extra uvloop install + import support if in python env (#2258)
• Fix --experimental-string-processing crash when matching parens are not found (#2283)
• Make sure to split lines that start with a string operator (#2286)
• Fix regular expression that black uses to identify f-expressions (#2287)

Blackd

• Add a lower bound for the aiohttp-cors dependency. Only 0.4.0 or higher is supported. (#2231)

Packaging

• Release self-contained x86_64 MacOS binaries as part of the GitHub release pipeline (#2198)
• Always build binaries with the latest available Python (#2260)

Documentation

• Add discussion of magic comments to FAQ page (#2272)
• --experimental-string-processing will be enabled by default in the future (#2273)
• Fix typos discovered by codespell (#2228)
• Fix Vim plugin installation instructions. (#2235)
• Add new Frequently Asked Questions page (#2247)
• Fix encoding + symlink issues preventing proper build on Windows (#2262)

21.5b1

Black

• Refactor src/black/__init__.py into many files (#2206)

Documentation

• Replaced all remaining references to the master branch with the main branch. Some additional changes in the source code were also made. (#2210)
• Sigificantly reorganized the documentation to make much more sense. Check them out by heading over to the stable docs on RTD. (#2174)

21.5b0

Black

• Set --pyi mode if --stdin-filename ends in .pyi (#2169)
• Stop detecting target version as Python 3.9+ with pre-PEP-614 decorators that are being called but with no arguments (#2182)

Black-Primer

• Add --no-diff to black-primer to suppress formatting changes (#2187)

21.4b2

Black

• Fix crash if the user configuration directory is inaccessible. (#2158)

• Clarify circumstances in which Black may change the AST (#2159)

• Allow .gitignore rules to be overridden by specifying exclude in pyproject.toml or on the command line. (#2170)

Packaging

• Install primer.json (used by black-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. Now Black 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 the X-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 preceding yield 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 the unicode_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/)