## Change Log ### Unreleased #### _Black_ - `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) - 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) - use lowercase hex strings (#1692) #### _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](#blackd) 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](http://mpastell.com/pweave/) and [Spyder IDE](https://www.spyder-ide.org/) 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](https://en.wikipedia.org/wiki/Fluent_interface) 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](https://pre-commit.com) 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](http://www.sphinx-doc.org/en/stable/ext/autodoc.html#directive-autoattribute) (#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](https://github.com/python/peps/commit/c59c4376ad233a62ca4b3a6060c81368bd21e85b) (#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/)