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# Change Log

## 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://pythonhosted.org/spyder/) 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/)


