v22.12.0

Compare Source

Preview style

• Enforce empty lines before classes and functions with sticky leading comments (#​3302)
• Reformat empty and whitespace-only files as either an empty file (if no newline is
  present) or as a single newline character (if a newline is present) (#​3348)
• Implicitly concatenated strings used as function args are now wrapped inside
  parentheses (#​3307)
• For assignment statements, prefer splitting the right hand side if the left hand side
  fits on a single line (#​3368)
• Correctly handle trailing commas that are inside a line's leading non-nested parens
  (#​3370)

Configuration

• Fix incorrectly applied .gitignore rules by considering the .gitignore location
  and the relative path to the target file (#​3338)
• Fix incorrectly ignoring .gitignore presence when more than one source directory is
  specified (#​3336)

Parser

• Parsing support has been added for walruses inside generator expression that are
  passed as function args (for example,
  any(match := my_re.match(text) for text in texts)) (#​3327).

Integrations

• Vim plugin: Optionally allow using the system installation of Black via
  let g:black_use_virtualenv = 0(#​3309)

v22.10.0

Compare Source

Highlights

• Runtime support for Python 3.6 has been removed. Formatting 3.6 code will still be
  supported until further notice.

Stable style

• Fix a crash when # fmt: on is used on a different block level than # fmt: off
  (#​3281)

Preview style

• Fix a crash when formatting some dicts with parenthesis-wrapped long string keys
  (#​3262)

Configuration

• .ipynb_checkpoints directories are now excluded by default (#​3293)
• Add --skip-source-first-line / -x option to ignore the first line of source code
  while formatting (#​3299)

Packaging

• Executables made with PyInstaller will no longer crash when formatting several files
  at once on macOS. Native x86-64 executables for macOS are available once again.
  (#​3275)
• Hatchling is now used as the build backend. This will not have any effect for users
  who install Black with its wheels from PyPI. (#​3233)
• Faster compiled wheels are now available for CPython 3.11 (#​3276)

Blackd

• Windows style (CRLF) newlines will be preserved (#​3257).

Integrations

• Vim plugin: add flag (g:black_preview) to enable/disable the preview style (#​3246)
• Update GitHub Action to support formatting of Jupyter Notebook files via a jupyter
  option (#​3282)
• Update GitHub Action to support use of version specifiers (e.g. <23) for Black
  version (#​3265)

v22.8.0

Compare Source

Highlights

• Python 3.11 is now supported, except for blackd as aiohttp does not support 3.11 as
  of publishing (#​3234)
• This is the last release that supports running Black on Python 3.6 (formatting 3.6
  code will continue to be supported until further notice)
• Reword the stability policy to say that we may, in rare cases, make changes that
  affect code that was not previously formatted by Black (#​3155)

Stable style

• Fix an infinite loop when using # fmt: on/off in the middle of an expression or code
  block (#​3158)
• Fix incorrect handling of # fmt: skip on colon (:) lines (#​3148)
• Comments are no longer deleted when a line had spaces removed around power operators
  (#​2874)

Preview style

• Single-character closing docstring quotes are no longer moved to their own line as
  this is invalid. This was a bug introduced in version 22.6.0. (#​3166)
• --skip-string-normalization / -S now prevents docstring prefixes from being
  normalized as expected (#​3168)
• When using --skip-magic-trailing-comma or -C, trailing commas are stripped from
  subscript expressions with more than 1 element (#​3209)
• Implicitly concatenated strings inside a list, set, or tuple are now wrapped inside
  parentheses (#​3162)
• Fix a string merging/split issue when a comment is present in the middle of implicitly
  concatenated strings on its own line (#​3227)

Blackd

• blackd now supports enabling the preview style via the X-Preview header (#​3217)

Configuration

• Black now uses the presence of debug f-strings to detect target version (#​3215)
• Fix misdetection of project root and verbose logging of sources in cases involving
  --stdin-filename (#​3216)
• Immediate .gitignore files in source directories given on the command line are now
  also respected, previously only .gitignore files in the project root and
  automatically discovered directories were respected (#​3237)

Documentation

• Recommend using BlackConnect in IntelliJ IDEs (#​3150)

Integrations

• Vim plugin: prefix messages with Black: so it's clear they come from Black (#​3194)
• Docker: changed to a /opt/venv installation + added to PATH to be available to
  non-root users (#​3202)

Output

• Change from deprecated asyncio.get_event_loop() to create our event loop which
  removes DeprecationWarning (#​3164)
• Remove logging from internal blib2to3 library since it regularly emits error logs
  about failed caching that can and should be ignored (#​3193)

Parser

• Type comments are now included in the AST equivalence check consistently so accidental
  deletion raises an error. Though type comments can't be tracked when running on PyPy
  3.7 due to standard library limitations. (#​2874)

Performance

• Reduce Black's startup time when formatting a single file by 15-30% (#​3211)

v22.6.0

Compare Source

Style

• Fix unstable formatting involving #fmt: skip and # fmt:skip comments (notice the
  lack of spaces) (#​2970)

Preview style

• Docstring quotes are no longer moved if it would violate the line length limit (#​3044)
• Parentheses around return annotations are now managed (#​2990)
• Remove unnecessary parentheses around awaited objects (#​2991)
• Remove unnecessary parentheses in with statements (#​2926)
• Remove trailing newlines after code block open (#​3035)

Integrations

• Add scripts/migrate-black.py script to ease introduction of Black to a Git project
  (#​3038)

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)
• PEP 646 syntax (for example,
  Array[Batch, *Shape] or def fn(*args: *T) -> None) is now supported (#​3071)

Vim Plugin

• Fix strtobool function. It didn't parse true/on/false/off. (#​3025)