<a href="https://black.readthedocs.io/en/stable/?badge=stable"><img alt="Documentation Status" src="https://readthedocs.org/projects/black/badge/?version=stable"></a>
<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>
<a href="https://github.com/ambv/black/blob/master/LICENSE"><img alt="License: MIT" src="https://black.readthedocs.io/en/stable/_static/license.svg"></a>
-<a href="https://pypi.python.org/pypi/black"><img alt="PyPI" src="https://black.readthedocs.io/en/stable/_static/pypi.svg"></a>
+<a href="https://pypi.org/project/black/"><img alt="PyPI" src="https://black.readthedocs.io/en/stable/_static/pypi.svg"></a>
+<a href="https://pepy.tech/project/black"><img alt="Downloads" src="https://pepy.tech/badge/black"></a>
<a href="https://github.com/ambv/black"><img alt="Code style: black" src="https://img.shields.io/badge/code%20style-black-000000.svg"></a>
</p>
*Black* makes code review faster by producing the smallest diffs
possible.
+Try it out now using the [Black Playground](https://black.now.sh).
+
---
*Contents:* **[Installation and usage](#installation-and-usage)** |
**[Code style](#the-black-code-style)** |
**[pyproject.toml](#pyprojecttoml)** |
**[Editor integration](#editor-integration)** |
+**[blackd](#blackd)** |
**[Version control integration](#version-control-integration)** |
**[Ignoring unmodified files](#ignoring-unmodified-files)** |
**[Testimonials](#testimonials)** |
black [OPTIONS] [SRC]...
Options:
- -l, --line-length INTEGER Where to wrap around. [default: 88]
- --py36 Allow using Python 3.6-only syntax on all input
- files. This will put trailing commas in function
- signatures and calls also after *args and
- **kwargs. [default: per-file auto-detection]
- --pyi Format all input files like typing stubs
- regardless of file extension (useful when piping
- source on standard input).
+ -l, --line-length INTEGER How many characters per line to allow.
+ [default: 88]
+ -t, --target-version [py27|py33|py34|py35|py36|py37|py38]
+ Python versions that should be supported by
+ Black's output. [default: per-file auto-
+ detection]
+ --pyi Format all input files like typing stubs
+ regardless of file extension (useful when
+ piping source on standard input).
-S, --skip-string-normalization
- Don't normalize string quotes or prefixes.
- --check Don't write the files back, just return the
- status. Return code 0 means nothing would
- change. Return code 1 means some files would be
- reformatted. Return code 123 means there was an
- internal error.
- --diff Don't write the files back, just output a diff
- for each file on stdout.
- --fast / --safe If --fast given, skip temporary sanity checks.
- [default: --safe]
- --include TEXT A regular expression that matches files and
- directories that should be included on
- recursive searches. On Windows, use forward
- slashes for directories. [default: \.pyi?$]
- --exclude TEXT A regular expression that matches files and
- directories that should be excluded on
- recursive searches. On Windows, use forward
- slashes for directories. [default:
- build/|buck-out/|dist/|_build/|\.git/|\.hg/|
- \.mypy_cache/|\.tox/|\.venv/]
- -q, --quiet Don't emit non-error messages to stderr. Errors
- are still emitted, silence those with
- 2>/dev/null.
- -v, --verbose Also emit messages to stderr about files
- that were not changed or were ignored due to
- --exclude=.
- --version Show the version and exit.
- --config PATH Read configuration from PATH.
- --help Show this message and exit.
+ Don't normalize string quotes or prefixes.
+ --check Don't write the files back, just return the
+ status. Return code 0 means nothing would
+ change. Return code 1 means some files
+ would be reformatted. Return code 123 means
+ there was an internal error.
+ --diff Don't write the files back, just output a
+ diff for each file on stdout.
+ --fast / --safe If --fast given, skip temporary sanity
+ checks. [default: --safe]
+ --include TEXT A regular expression that matches files and
+ directories that should be included on
+ recursive searches. An empty value means
+ all files are included regardless of the
+ name. Use forward slashes for directories
+ on all platforms (Windows, too). Exclusions
+ are calculated first, inclusions later.
+ [default: \.pyi?$]
+ --exclude TEXT A regular expression that matches files and
+ directories that should be excluded on
+ recursive searches. An empty value means no
+ paths are excluded. Use forward slashes for
+ directories on all platforms (Windows, too).
+ Exclusions are calculated first, inclusions
+ later. [default: /(\.eggs|\.git|\.hg|\.mypy
+ _cache|\.nox|\.tox|\.venv|_build|buck-
+ out|build|dist)/]
+ -q, --quiet Don't emit non-error messages to stderr.
+ Errors are still emitted, silence those with
+ 2>/dev/null.
+ -v, --verbose Also emit messages to stderr about files
+ that were not changed or were ignored due to
+ --exclude=.
+ --version Show the version and exit.
+ --config PATH Read configuration from PATH.
+ -h, --help Show this message and exit.
```
*Black* is a well-behaved Unix-style command-line tool:
*Black* reformats entire files in place. It is not configurable. It
doesn't take previous formatting into account. It doesn't reformat
-blocks that start with `# fmt: off` and end with `# fmt: on`. It also
+blocks that start with `# fmt: off` and end with `# fmt: on`. `# fmt: on/off`
+have to be on the same level of indentation. It also
recognizes [YAPF](https://github.com/google/yapf)'s block comments to
the same effect, as a courtesy for straddling code.
```py3
# in:
-TracebackException.from_exception(exc, limit, lookup_lines, capture_locals)
+ImportantClass.important_method(exc, limit, lookup_lines, capture_locals, extra_argument)
# out:
-TracebackException.from_exception(
- exc, limit, lookup_lines, capture_locals
+ImportantClass.important_method(
+ exc, limit, lookup_lines, capture_locals, extra_argument
)
```
```py3
# in:
-def very_important_function(template: str, *variables, file: os.PathLike, debug: bool = False):
+def very_important_function(template: str, *variables, file: os.PathLike, engine: str, header: bool = True, debug: bool = False):
"""Applies `variables` to the `template` and writes to `file`."""
with open(file, 'w') as f:
...
template: str,
*variables,
file: os.PathLike,
+ engine: str,
+ header: bool = True,
debug: bool = False,
):
"""Applies `variables` to the `template` and writes to `file`."""
multi_line_output=3
include_trailing_comma=True
force_grid_wrap=0
-combine_as_imports=True
+use_parentheses=True
line_length=88
```
The equivalent command line is:
```
-$ isort --multi-line=3 --trailing-comma --force-grid-wrap=0 --combine-as --line-width=88 [ file.py ]
+$ isort --multi-line=3 --trailing-comma --force-grid-wrap=0 --use-parentheses --line-width=88 [ file.py ]
```
</details>
```
You'll find *Black*'s own .flake8 config file is configured like this.
-If you're curious about the reasoning behind B950, Bugbear's documentation
+If you're curious about the reasoning behind B950,
+[Bugbear's documentation](https://github.com/PyCQA/flake8-bugbear#opinionated-warnings)
explains it. The tl;dr is "it's like highway speed limits, we won't
bother you if you overdo it by a few km/h".
[#26](https://github.com/ambv/black/issues/26) for details).
Why settle on double quotes? They anticipate apostrophes in English
-text. They match the docstring standard described in PEP 257. An
-empty string in double quotes (`""`) is impossible to confuse with
+text. They match the docstring standard described in [PEP 257](https://www.python.org/dev/peps/pep-0257/#what-is-a-docstring).
+An empty string in double quotes (`""`) is impossible to confuse with
a one double-quote regardless of fonts and syntax highlighting used.
On top of this, double quotes for strings are consistent with C which
Python interacts a lot with.
pass `--skip-string-normalization` on the command line. This is meant as
an adoption helper, avoid using this for new projects.
+### Numeric literals
+
+*Black* standardizes most numeric literals to use lowercase letters for the
+syntactic parts and uppercase letters for the digits themselves: `0xAB`
+instead of `0XAB` and `1e10` instead of `1E10`. Python 2 long literals are
+styled as `2L` instead of `2l` to avoid confusion between `l` and `1`.
+
### Line breaks & binary operators
If you're running with `--verbose`, you will see a blue message if
a file was found and used.
+Please note `blackd` will not use `pyproject.toml` configuration.
+
### Configuration format
```toml
[tool.black]
line-length = 88
-py36 = true
+target_version = ['py37']
include = '\.pyi?$'
exclude = '''
-/(
- \.git
- | \.hg
- | \.mypy_cache
- | \.tox
- | \.venv
- | _build
- | buck-out
- | build
- | dist
-
- # The following are specific to Black, you probably don't want those.
- | blib2to3
- | tests/data
-)/
+
+(
+ /(
+ \.eggs # exclude a few common directories in the
+ | \.git # root of the project
+ | \.hg
+ | \.mypy_cache
+ | \.tox
+ | \.venv
+ | _build
+ | buck-out
+ | build
+ | dist
+ )/
+ | foo.py # also separately exclude a file named foo.py in
+ # the root of the project
+)
'''
```
- Name: Black
- Description: Black is the uncompromising Python code formatter.
- Program: <install_location_from_step_2>
- - Arguments: $FilePath$
+ - Arguments: `$FilePath$`
5. Format the currently opened file by selecting `Tools -> External Tools -> black`.
- Alternatively, you can set a keyboard shortcut by navigating to `Preferences -> Keymap -> External Tools -> External Tools - Black`.
+6. Optionally, run Black on every file save:
+
+ 1. Make sure you have the [File Watcher](https://plugins.jetbrains.com/plugin/7177-file-watchers) plugin installed.
+ 2. Go to `Preferences -> Tools -> File Watchers` and click `+` to add a new watcher:
+ - Name: Black
+ - File type: Python
+ - Scope: Project Files
+ - Program: <install_location_from_step_2>
+ - Arguments: `$FilePath$`
+ - Output paths to refresh: `$FilePathRelativeToProjectRoot$`
+ - Working directory: `$ProjectFileDir$`
+ - Uncheck "Auto-save edited files to trigger the watcher"
### Vim
Commands and shortcuts:
-* `,=` or `:Black` to format the entire file (ranges not supported);
+* `:Black` to format the entire file (ranges not supported);
* `:BlackUpgrade` to upgrade *Black* inside the virtualenv;
* `:BlackVersion` to get the current version of *Black* inside the
virtualenv.
To install with [vim-plug](https://github.com/junegunn/vim-plug):
```
-Plug 'ambv/black',
+Plug 'ambv/black'
```
or with [Vundle](https://github.com/VundleVim/Vundle.vim):
To run *Black* on save, add the following line to `.vimrc` or `init.vim`:
```
-autocmd BufWritePost *.py execute ':Black'
+autocmd BufWritePre *.py execute ':Black'
```
**How to get Vim with Python 3.6?**
Use [sublack plugin](https://github.com/jgirardet/sublack).
-### IPython Notebook Magic
+### Jupyter Notebook Magic
Use [blackcellmagic](https://github.com/csurfer/blackcellmagic).
+### Python Language Server
+
+If your editor supports the [Language Server Protocol](https://langserver.org/)
+(Atom, Sublime Text, Visual Studio Code and many more), you can use
+the [Python Language Server](https://github.com/palantir/python-language-server) with the
+[pyls-black](https://github.com/rupert/pyls-black) plugin.
+
+
+### Atom/Nuclide
+
+Use [python-black](https://atom.io/packages/python-black).
+
+
### Other editors
-Atom/Nuclide integration is planned by the author, others will
-require external contributions.
+Other editors will require external contributions.
Patches welcome! ✨ 🍰 ✨
This can be used for example with PyCharm's [File Watchers](https://www.jetbrains.com/help/pycharm/file-watchers.html).
+## blackd
+
+`blackd` is a small HTTP server that exposes *Black*'s functionality over
+a simple protocol. The main benefit of using it is to avoid paying the
+cost of starting up a new *Black* process every time you want to blacken
+a file.
+
+### Usage
+
+`blackd` is not packaged alongside *Black* by default because it has additional
+dependencies. You will need to do `pip install black[d]` to install it.
+
+You can start the server on the default port, binding only to the local interface
+by running `blackd`. You will see a single line mentioning the server's version,
+and the host and port it's listening on. `blackd` will then print an access log
+similar to most web servers on standard output, merged with any exception traces
+caused by invalid formatting requests.
+
+`blackd` provides even less options than *Black*. You can see them by running
+`blackd --help`:
+
+```text
+Usage: blackd [OPTIONS]
+
+Options:
+ --bind-host TEXT Address to bind the server to.
+ --bind-port INTEGER Port to listen on
+ --version Show the version and exit.
+ -h, --help Show this message and exit.
+```
+
+### Protocol
+
+`blackd` only accepts `POST` requests at the `/` path. The body of the request
+should contain the python source code to be formatted, encoded
+according to the `charset` field in the `Content-Type` request header. If no
+`charset` is specified, `blackd` assumes `UTF-8`.
+
+There are a few HTTP headers that control how the source is formatted. These
+correspond to command line flags for *Black*. There is one exception to this:
+`X-Protocol-Version` which if present, should have the value `1`, otherwise the
+request is rejected with `HTTP 501` (Not Implemented).
+
+The headers controlling how code is formatted are:
+
+ - `X-Line-Length`: corresponds to the `--line-length` command line flag.
+ - `X-Skip-String-Normalization`: corresponds to the `--skip-string-normalization`
+ command line flag. If present and its value is not the empty string, no string
+ normalization will be performed.
+ - `X-Fast-Or-Safe`: if set to `fast`, `blackd` will act as *Black* does when
+ passed the `--fast` command line flag.
+ - `X-Python-Variant`: if set to `pyi`, `blackd` will act as *Black* does when
+ passed the `--pyi` command line flag. Otherwise, its value must correspond to
+ a Python version or a set of comma-separated Python versions, optionally
+ prefixed with `py`. For example, to request code that is compatible
+ with Python 3.5 and 3.6, set the header to `py3.5,py3.6`.
+
+If any of these headers are set to invalid values, `blackd` returns a `HTTP 400`
+error response, mentioning the name of the problematic header in the message body.
+
+Apart from the above, `blackd` can produce the following response codes:
+
+ - `HTTP 204`: If the input is already well-formatted. The response body is
+ empty.
+ - `HTTP 200`: If formatting was needed on the input. The response body
+ contains the blackened Python code, and the `Content-Type` header is set
+ accordingly.
+ - `HTTP 400`: If the input contains a syntax error. Details of the error are
+ returned in the response body.
+ - `HTTP 500`: If there was any kind of error while trying to format the input.
+ The response body contains a textual representation of the error.
## Version control integration
is run. The file is non-portable. The standard location on common operating systems
is:
-* Windows: `C:\\Users\<username>\AppData\Local\black\black\Cache\<version>\cache.<line-length>.pickle`
-* macOS: `/Users/<username>/Library/Caches/black/<version>/cache.<line-length>.pickle`
-* Linux: `/home/<username>/.cache/black/<version>/cache.<line-length>.pickle`
+* Windows: `C:\\Users\<username>\AppData\Local\black\black\Cache\<version>\cache.<line-length>.<file-mode>.pickle`
+* macOS: `/Users/<username>/Library/Caches/black/<version>/cache.<line-length>.<file-mode>.pickle`
+* Linux: `/home/<username>/.cache/black/<version>/cache.<line-length>.<file-mode>.pickle`
+
+`file-mode` is an int flag that determines whether the file was formatted as 3.6+ only,
+as .pyi, and whether string normalization was omitted.
## Testimonials
> *Black* is opinionated so you don't have to be.
-**Hynek Schlawack**, [creator of `attrs`](http://www.attrs.org/), core
+**Hynek Schlawack**, [creator of `attrs`](https://www.attrs.org/), core
developer of Twisted and CPython:
> An auto-formatter that doesn't suck is all I want for Xmas!
[](https://github.com/ambv/black)
```
+Using the badge in README.rst:
+```
+.. image:: https://img.shields.io/badge/code%20style-black-000000.svg
+ :target: https://github.com/ambv/black
+```
+
Looks like this: [](https://github.com/ambv/black)
## Change Log
+### 19.3b0
+
+* new option `--target-version` to control which Python versions
+ *Black*-formatted code should target (#618)
+
+* removed `--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)
+
+* improved performance of formatting deeply nested data structures (#509)
+
+* `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 cannibalizing backslashes during string normalization
+* fixed a crash due to symbolic links pointing outside of the project directory (#338)
+
### 18.6b2
### 18.3a2
* changed positioning of binary operators to occur at beginning of lines
- instead of at the end, following [a recent change to PEP8](https://github.com/python/peps/commit/c59c4376ad233a62ca4b3a6060c81368bd21e85b)
+ 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
Maintained with [Carol Willing](mailto:carolcode@willingconsulting.com),
[Carl Meyer](mailto:carl@oddbird.net),
+[Jelle Zijlstra](mailto:jelle.zijlstra@gmail.com),
[Mika Naylor](mailto:mail@autophagy.io), and
[Zsolt Dollenstein](mailto:zsol.zsol@gmail.com).
* [Artem Malyshev](mailto:proofit404@gmail.com)
* [Christian Heimes](mailto:christian@python.org)
* [Daniel M. Capella](mailto:polycitizen@gmail.com)
-* [Eli Treuherz](mailto:eli.treuherz@cgi.com)
+* [Eli Treuherz](mailto:eli@treuherz.com)
+* hauntsaninja
* Hugo van Kemenade
* [Ivan Katanić](mailto:ivan.katanic@gmail.com)
-* [Jelle Zijlstra](mailto:jelle.zijlstra@gmail.com)
* [Jonas Obrist](mailto:ojiidotch@gmail.com)
* [Luka Sterbic](mailto:luka.sterbic@gmail.com)
* [Miguel Gaiowski](mailto:miggaiowski@gmail.com)
+* [Miroslav Shubernetskiy](mailto:miroslav@miki725.com)
+* [Neraste](mailto:neraste.herr10@gmail.com)
* [Osaetin Daniel](mailto:osaetindaniel@gmail.com)
* [Peter Bengtsson](mailto:mail@peterbe.com)
* [Stavros Korokithakis](mailto:hi@stavros.io)
* [Sunil Kapil](mailto:snlkapil@gmail.com)
* [Vishwas B Sharma](mailto:sharma.vishwas88@gmail.com)
+* [Chuck Wooters](mailto:chuck.wooters@microsoft.com)
projects / etc / vim.git / blobdiff