X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/d29303c9884e1ef715851d69acc5d54f84441720..5d978df8b54d4fb102142508353a04932a4b5b04:/README.md
diff --git a/README.md b/README.md
index 04905e2..d34ce14 100644
--- a/README.md
+++ b/README.md
@@ -5,11 +5,13 @@
+
+
@@ -31,12 +33,14 @@ Try it out now using the [Black Playground](https://black.now.sh). Watch the
---
_Contents:_ **[Installation and usage](#installation-and-usage)** |
-**[Code style](#the-black-code-style)** | **[pyproject.toml](#pyprojecttoml)** |
-**[Editor integration](#editor-integration)** | **[blackd](#blackd)** |
+**[Code style](#the-black-code-style)** | **[Pragmatism](#pragmatism)** |
+**[pyproject.toml](#pyprojecttoml)** | **[Editor integration](#editor-integration)** |
+**[blackd](#blackd)** | **[black-primer](#black-primer)** |
**[Version control integration](#version-control-integration)** |
+**[GitHub Actions](#github-actions)** |
**[Ignoring unmodified files](#ignoring-unmodified-files)** | **[Used by](#used-by)** |
**[Testimonials](#testimonials)** | **[Show your style](#show-your-style)** |
-**[Contributing](#contributing-to-black)** | **[Change Log](#change-log)** |
+**[Contributing](#contributing-to-black)** | **[Change log](#change-log)** |
**[Authors](#authors)**
---
@@ -48,49 +52,66 @@ _Contents:_ **[Installation and usage](#installation-and-usage)** |
_Black_ can be installed by running `pip install black`. It requires Python 3.6.0+ to
run but you can reformat Python 2 code with it, too.
+#### Install from GitHub
+
+If you can't wait for the latest _hotness_ and want to install from GitHub, use:
+
+`pip install git+git://github.com/psf/black`
+
### Usage
To get started right away with sensible defaults:
-```
+```sh
black {source_file_or_directory}
```
+You can run _Black_ as a package if running it as a script doesn't work:
+
+```sh
+python -m black {source_file_or_directory}
+```
+
### Command line options
_Black_ doesn't provide many options. You can list them by running `black --help`:
```text
-black [OPTIONS] [SRC]...
+Usage: black [OPTIONS] [SRC]...
+
+ The uncompromising code formatter.
Options:
-c, --code TEXT Format the code passed in as a string.
-l, --line-length INTEGER How many characters per line to allow.
[default: 88]
- -t, --target-version [py27|py33|py34|py35|py36|py37|py38]
+
+ -t, --target-version [py27|py33|py34|py35|py36|py37|py38|py39]
Python versions that should be supported by
Black's output. [default: per-file auto-
detection]
- --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. Deprecated; use
- --target-version instead. [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
+ 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.
+
+ --color / --no-color Show colored diff. Only applies when
+ `--diff` is given.
+
--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
@@ -99,6 +120,7 @@ Options:
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
@@ -106,16 +128,23 @@ Options:
directories on all platforms (Windows, too).
Exclusions are calculated first, inclusions
later. [default: /(\.eggs|\.git|\.hg|\.mypy
- _cache|\.nox|\.tox|\.venv|_build|buck-
+ _cache|\.nox|\.tox|\.venv|\.svn|_build|buck-
out|build|dist)/]
+
+ --force-exclude TEXT Like --exclude, but files and directories
+ matching this regex will be excluded even
+ when they are passed explicitly as arguments.
+
-q, --quiet Don't emit non-error messages to stderr.
- Errors are still emitted, silence those with
+ 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.
+ --config FILE Read configuration from FILE path.
-h, --help Show this message and exit.
```
@@ -127,367 +156,97 @@ _Black_ is a well-behaved Unix-style command-line tool:
- it only outputs messages to users on standard error;
- exits with code 0 unless an internal error occurred (or `--check` was used).
-### NOTE: This is a beta product
-
-_Black_ is already [successfully used](#used-by) by many projects, small and big. It
-also sports a decent test suite. However, it is still very new. Things will probably be
-wonky for a while. This is made explicit by the "Beta" trove classifier, as well as by
-the "b" in the version number. What this means for you is that **until the formatter
-becomes stable, you should expect some formatting to change in the future**. That being
-said, no drastic stylistic changes are planned, mostly responses to bug reports.
+### Using _Black_ with other tools
-Also, as a temporary safety measure, _Black_ will check that the reformatted code still
-produces a valid AST that is equivalent to the original. This slows it down. If you're
-feeling confident, use `--fast`.
-
-## The _Black_ code style
-
-_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`. `# 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.
-
-### How _Black_ wraps lines
-
-_Black_ ignores previous formatting and applies uniform horizontal and vertical
-whitespace to your code. The rules for horizontal whitespace can be summarized as: do
-whatever makes `pycodestyle` happy. The coding style used by _Black_ can be viewed as a
-strict subset of PEP 8.
-
-As for vertical whitespace, _Black_ tries to render one full expression or simple
-statement per line. If this fits the allotted line length, great.
-
-```py3
-# in:
+While _Black_ enforces formatting that conforms to PEP 8, other tools may raise warnings
+about _Black_'s changes or will overwrite _Black_'s changes. A good example of this is
+[isort](https://pypi.org/p/isort). Since _Black_ is barely configurable, these tools
+should be configured to neither warn about nor overwrite _Black_'s changes.
-j = [1,
- 2,
- 3
-]
+Actual details on _Black_ compatible configurations for various tools can be found in
+[compatible_configs](https://github.com/psf/black/blob/master/docs/compatible_configs.md#black-compatible-configurations).
-# out:
+### Migrating your code style without ruining git blame
-j = [1, 2, 3]
-```
-
-If not, _Black_ will look at the contents of the first outer matching brackets and put
-that in a separate indented line.
-
-```py3
-# in:
+A long-standing argument against moving to automated code formatters like _Black_ is
+that the migration will clutter up the output of `git blame`. This was a valid argument,
+but since Git version 2.23, Git natively supports
+[ignoring revisions in blame](https://git-scm.com/docs/git-blame#Documentation/git-blame.txt---ignore-revltrevgt)
+with the `--ignore-rev` option. You can also pass a file listing the revisions to ignore
+using the `--ignore-revs-file` option. The changes made by the revision will be ignored
+when assigning blame. Lines modified by an ignored revision will be blamed on the
+previous revision that modified those lines.
-ImportantClass.important_method(exc, limit, lookup_lines, capture_locals, extra_argument)
+So when migrating your project's code style to _Black_, reformat everything and commit
+the changes (preferably in one massive commit). Then put the full 40 characters commit
+identifier(s) into a file.
-# out:
-
-ImportantClass.important_method(
- exc, limit, lookup_lines, capture_locals, extra_argument
-)
```
-
-If that still doesn't fit the bill, it will decompose the internal expression further
-using the same rule, indenting matching brackets every time. If the contents of the
-matching brackets pair are comma-separated (like an argument list, or a dict literal,
-and so on) then _Black_ will first try to keep them on the same line with the matching
-brackets. If that doesn't work, it will put all of them in separate lines.
-
-```py3
-# in:
-
-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:
- ...
-
-# out:
-
-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:
- ...
+# Migrate code style to Black
+5b4ab991dede475d393e9d69ec388fd6bd949699
```
-You might have noticed that closing brackets are always dedented and that a trailing
-comma is always added. Such formatting produces smaller diffs; when you add or remove an
-element, it's always just one line. Also, having the closing bracket dedented provides a
-clear delimiter between two distinct sections of the code that otherwise share the same
-indentation level (like the arguments list and the docstring in the example above).
+Afterwards, you can pass that file to `git blame` and see clean and meaningful blame
+information.
-If a data structure literal (tuple, list, set, dict) or a line of "from" imports cannot
-fit in the allotted length, it's always split into one element per line. This minimizes
-diffs as well as enables readers of code to find which commit introduced a particular
-entry. This also makes _Black_ compatible with [isort](https://pypi.org/p/isort/) with
-the following configuration.
-
-
-A compatible `.isort.cfg`
-
-```
-[settings]
-multi_line_output=3
-include_trailing_comma=True
-force_grid_wrap=0
-use_parentheses=True
-line_length=88
+```console
+$ git blame important.py --ignore-revs-file .git-blame-ignore-revs
+7a1ae265 (John Smith 2019-04-15 15:55:13 -0400 1) def very_important_function(text, file):
+abdfd8b0 (Alice Doe 2019-09-23 11:39:32 -0400 2) text = text.lstrip()
+7a1ae265 (John Smith 2019-04-15 15:55:13 -0400 3) with open(file, "r+") as f:
+7a1ae265 (John Smith 2019-04-15 15:55:13 -0400 4) f.write(formatted)
```
-The equivalent command line is:
+You can even configure `git` to automatically ignore revisions listed in a file on every
+call to `git blame`.
+```console
+$ git config blame.ignoreRevsFile .git-blame-ignore-revs
```
-$ isort --multi-line=3 --trailing-comma --force-grid-wrap=0 --use-parentheses --line-width=88 [ file.py ]
-```
-
-
-### Line length
-
-You probably noticed the peculiar default line length. _Black_ defaults to 88 characters
-per line, which happens to be 10% over 80. This number was found to produce
-significantly shorter files than sticking with 80 (the most popular), or even 79 (used
-by the standard library). In general,
-[90-ish seems like the wise choice](https://youtu.be/wf-BqAjZb8M?t=260).
-
-If you're paid by the line of code you write, you can pass `--line-length` with a lower
-number. _Black_ will try to respect that. However, sometimes it won't be able to without
-breaking other rules. In those rare cases, auto-formatted code will exceed your allotted
-limit.
-
-You can also increase it, but remember that people with sight disabilities find it
-harder to work with line lengths exceeding 100 characters. It also adversely affects
-side-by-side diff review on typical screen resolutions. Long lines also make it harder
-to present code neatly in documentation or talk slides.
-
-If you're using Flake8, you can bump `max-line-length` to 88 and forget about it.
-Alternatively, use [Bugbear](https://github.com/PyCQA/flake8-bugbear)'s B950 warning
-instead of E501 and keep the max line length at 80 which you are probably already using.
-You'd do it like this:
-
-```ini
-[flake8]
-max-line-length = 80
-...
-select = C,E,F,W,B,B950
-ignore = E203, E501, W503
-```
+**The one caveat is that GitHub and GitLab do not yet support ignoring revisions using
+their native UI of blame.** So blame information will be cluttered with a reformatting
+commit on those platforms. (If you'd like this feature, there's an open issue for
+[GitLab](https://gitlab.com/gitlab-org/gitlab/-/issues/31423) and please let GitHub
+know!)
-You'll find _Black_'s own .flake8 config file is configured like this. Explanation of
-why W503 and E203 are disabled can be found further in this documentation. And 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".
+### NOTE: This is a beta product
-**If you're looking for a minimal, black-compatible flake8 configuration:**
+_Black_ is already [successfully used](https://github.com/psf/black#used-by) by many
+projects, small and big. It also sports a decent test suite. However, it is still very
+new. Things will probably be wonky for a while. This is made explicit by the "Beta"
+trove classifier, as well as by the "b" in the version number. What this means for you
+is that **until the formatter becomes stable, you should expect some formatting to
+change in the future**. That being said, no drastic stylistic changes are planned,
+mostly responses to bug reports.
-```ini
-[flake8]
-max-line-length = 88
-extend-ignore = E203
-```
+Also, as a temporary safety measure, _Black_ will check that the reformatted code still
+produces a valid AST that is equivalent to the original. This slows it down. If you're
+feeling confident, use `--fast`.
-### Empty lines
+## The _Black_ code style
-_Black_ avoids spurious vertical whitespace. This is in the spirit of PEP 8 which says
-that in-function vertical whitespace should only be used sparingly.
-
-_Black_ will allow single empty lines inside functions, and single and double empty
-lines on module level left by the original editors, except when they're within
-parenthesized expressions. Since such expressions are always reformatted to fit minimal
-space, this whitespace is lost.
+_Black_ is a PEP 8 compliant opinionated formatter. _Black_ reformats entire files in
+place. It is not configurable. It doesn't take previous formatting into account. Your
+main option of configuring _Black_ is that it doesn't reformat blocks that start with
+`# fmt: off` and end with `# fmt: on`. `# fmt: on/off` have to be on the same level of
+indentation. To learn more about _Black_'s opinions, to go
+[the_black_code_style](https://github.com/psf/black/blob/master/docs/the_black_code_style.md).
-It will also insert proper spacing before and after function definitions. It's one line
-before and after inner functions and two lines before and after module-level functions
-and classes. _Black_ will not put empty lines between function/class definitions and
-standalone comments that immediately precede the given function/class.
+Please refer to this document before submitting an issue. What seems like a bug might be
+intended behaviour.
-_Black_ will enforce single empty lines between a class-level docstring and the first
-following field or method. This conforms to
-[PEP 257](https://www.python.org/dev/peps/pep-0257/#multi-line-docstrings).
-
-_Black_ won't insert empty lines after function docstrings unless that empty line is
-required due to an inner function starting immediately after.
-
-### Trailing commas
-
-_Black_ will add trailing commas to expressions that are split by comma where each
-element is on its own line. This includes function signatures.
-
-Unnecessary trailing commas are removed if an expression fits in one line. This makes it
-1% more likely that your line won't exceed the allotted line length limit. Moreover, in
-this scenario, if you added another argument to your call, you'd probably fit it in the
-same line anyway. That doesn't make diffs any larger.
-
-One exception to removing trailing commas is tuple expressions with just one element. In
-this case _Black_ won't touch the single trailing comma as this would unexpectedly
-change the underlying data type. Note that this is also the case when commas are used
-while indexing. This is a tuple in disguise: `numpy_array[3, ]`.
-
-One exception to adding trailing commas is function signatures containing `*`, `*args`,
-or `**kwargs`. In this case a trailing comma is only safe to use on Python 3.6. _Black_
-will detect if your file is already 3.6+ only and use trailing commas in this situation.
-If you wonder how it knows, it looks for f-strings and existing use of trailing commas
-in function signatures that have stars in them. In other words, if you'd like a trailing
-comma in this situation and _Black_ didn't recognize it was safe to do so, put it there
-manually and _Black_ will keep it.
-
-### Strings
-
-_Black_ prefers double quotes (`"` and `"""`) over single quotes (`'` and `'''`). It
-will replace the latter with the former as long as it does not result in more backslash
-escapes than before.
-
-_Black_ also standardizes string prefixes, making them always lowercase. On top of that,
-if your code is already Python 3.6+ only or it's using the `unicode_literals` future
-import, _Black_ will remove `u` from the string prefix as it is meaningless in those
-scenarios.
-
-The main reason to standardize on a single form of quotes is aesthetics. Having one kind
-of quotes everywhere reduces reader distraction. It will also enable a future version of
-_Black_ to merge consecutive string literals that ended up on the same line (see
-[#26](https://github.com/psf/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](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.
-
-On certain keyboard layouts like US English, typing single quotes is a bit easier than
-double quotes. The latter requires use of the Shift key. My recommendation here is to
-keep using whatever is faster to type and let _Black_ handle the transformation.
-
-If you are adopting _Black_ in a large project with pre-existing string conventions
-(like the popular
-["single quotes for data, double quotes for human-readable strings"](https://stackoverflow.com/a/56190)),
-you can 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
-
-_Black_ will break a line before a binary operator when splitting a block of code over
-multiple lines. This is so that _Black_ is compliant with the recent changes in the
-[PEP 8](https://www.python.org/dev/peps/pep-0008/#should-a-line-break-before-or-after-a-binary-operator)
-style guide, which emphasizes that this approach improves readability.
-
-This behaviour may raise `W503 line break before binary operator` warnings in style
-guide enforcement tools like Flake8. Since `W503` is not PEP 8 compliant, you should
-tell Flake8 to ignore these warnings.
-
-### Slices
-
-PEP 8
-[recommends](https://www.python.org/dev/peps/pep-0008/#whitespace-in-expressions-and-statements)
-to treat `:` in slices as a binary operator with the lowest priority, and to leave an
-equal amount of space on either side, except if a parameter is omitted (e.g.
-`ham[1 + 1 :]`). It also states that for extended slices, both `:` operators have to
-have the same amount of spacing, except if a parameter is omitted (`ham[1 + 1 ::]`).
-_Black_ enforces these rules consistently.
-
-This behaviour may raise `E203 whitespace before ':'` warnings in style guide
-enforcement tools like Flake8. Since `E203` is not PEP 8 compliant, you should tell
-Flake8 to ignore these warnings.
-
-### Parentheses
-
-Some parentheses are optional in the Python grammar. Any expression can be wrapped in a
-pair of parentheses to form an atom. There are a few interesting cases:
-
-- `if (...):`
-- `while (...):`
-- `for (...) in (...):`
-- `assert (...), (...)`
-- `from X import (...)`
-- assignments like:
- - `target = (...)`
- - `target: type = (...)`
- - `some, *un, packing = (...)`
- - `augmented += (...)`
-
-In those cases, parentheses are removed when the entire statement fits in one line, or
-if the inner expression doesn't have any delimiters to further split on. If there is
-only a single delimiter and the expression starts or ends with a bracket, the
-parenthesis can also be successfully omitted since the existing bracket pair will
-organize the expression neatly anyway. Otherwise, the parentheses are added.
-
-Please note that _Black_ does not add or remove any additional nested parentheses that
-you might want to have for clarity or further code organization. For example those
-parentheses are not going to be removed:
-
-```py3
-return not (this or that)
-decision = (maybe.this() and values > 0) or (maybe.that() and values < 0)
-```
+## Pragmatism
-### Call chains
-
-Some popular APIs, like ORMs, use call chaining. This API style is known as a
-[fluent interface](https://en.wikipedia.org/wiki/Fluent_interface). _Black_ formats
-those by treating dots that follow a call or an indexing operation like a very low
-priority delimiter. It's easier to show the behavior than to explain it. Look at the
-example:
-
-```py3
-def example(session):
- result = (
- session.query(models.Customer.id)
- .filter(
- models.Customer.account_id == account_id,
- models.Customer.email == email_address,
- )
- .order_by(models.Customer.id.asc())
- .all()
- )
-```
+Early versions of _Black_ used to be absolutist in some respects. They took after its
+initial author. This was fine at the time as it made the implementation simpler and
+there were not many users anyway. Not many edge cases were reported. As a mature tool,
+_Black_ does make some exceptions to rules it otherwise holds. This
+[section](https://github.com/psf/black/blob/master/docs/the_black_code_style.md#pragmatism)
+of `the_black_code_style` describes what those exceptions are and why this is the case.
-### Typing stub files
-
-PEP 484 describes the syntax for type hints in Python. One of the use cases for typing
-is providing type annotations for modules which cannot contain them directly (they might
-be written in C, or they might be third-party, or their implementation may be overly
-dynamic, and so on).
-
-To solve this,
-[stub files with the `.pyi` file extension](https://www.python.org/dev/peps/pep-0484/#stub-files)
-can be used to describe typing information for an external module. Those stub files omit
-the implementation of classes and functions they describe, instead they only contain the
-structure of the file (listing globals, functions, and classes with their members). The
-recommended code style for those files is more terse than PEP 8:
-
-- prefer `...` on the same line as the class/function signature;
-- avoid vertical whitespace between consecutive module-level functions, names, or
- methods and fields within a single class;
-- use a single blank line between top-level class definitions, or none if the classes
- are very small.
-
-_Black_ enforces the above rules. There are additional guidelines for formatting `.pyi`
-file that are not enforced yet but might be in a future version of the formatter:
-
-- all function bodies should be empty (contain `...` instead of the body);
-- do not use docstrings;
-- prefer `...` over `pass`;
-- for arguments with a default, use `...` instead of the actual default;
-- avoid using string literals in type annotations, stub files support forward references
- natively (like Python 3.7 code with `from __future__ import annotations`);
-- use variable annotations instead of type comments, even for stubs that target older
- versions of Python;
-- for arguments that default to `None`, use `Optional[]` explicitly;
-- use `float` instead of `Union[int, float]`.
+Please refer to this document before submitting an issue just like with the document
+above. What seems like a bug might be intended behaviour.
## pyproject.toml
@@ -502,7 +261,7 @@ from a `pyproject.toml` file. This is especially useful for specifying custom
[PEP 518](https://www.python.org/dev/peps/pep-0518/) defines `pyproject.toml` as a
configuration file to store build system requirements for Python projects. With the help
-of tools like [Poetry](https://poetry.eustace.io/) or
+of tools like [Poetry](https://python-poetry.org/) or
[Flit](https://flit.readthedocs.io/en/latest/) it can fully replace the need for
`setup.py` and `setup.cfg` files.
@@ -536,7 +295,7 @@ the equivalent of r-strings in Python. Multiline strings are treated as verbose
expressions by Black. Use `[ ]` to denote a significant space character.
-Example `pyproject.toml`
+Example pyproject.toml
```toml
[tool.black]
@@ -578,308 +337,31 @@ file hierarchy.
## Editor integration
-### Emacs
-
-Use [proofit404/blacken](https://github.com/proofit404/blacken) or
-[Elpy](https://github.com/jorgenschaefer/elpy).
-
-### PyCharm/IntelliJ IDEA
-
-1. Install `black`.
-
-```console
-$ pip install black
-```
-
-2. Locate your `black` installation folder.
-
-On macOS / Linux / BSD:
-
-```console
-$ which black
-/usr/local/bin/black # possible location
-```
-
-On Windows:
-
-```console
-$ where black
-%LocalAppData%\Programs\Python\Python36-32\Scripts\black.exe # possible location
-```
-
-3. Open External tools in PyCharm/IntelliJ IDEA
-
-On macOS:
-
-`PyCharm -> Preferences -> Tools -> External Tools`
-
-On Windows / Linux / BSD:
-
-`File -> Settings -> Tools -> External Tools`
-
-4. Click the + icon to add a new external tool with the following values:
-
- - Name: Black
- - Description: Black is the uncompromising Python code formatter.
- - Program:
- - 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 or Settings -> 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 or Settings -> Tools -> File Watchers` and click `+` to add a
- new watcher:
- - Name: Black
- - File type: Python
- - Scope: Project Files
- - Program:
- - Arguments: `$FilePath$`
- - Output paths to refresh: `$FilePath$`
- - Working directory: `$ProjectFileDir$`
-
- - Uncheck "Auto-save edited files to trigger the watcher"
-
-### Wing IDE
-
-Wing supports black via the OS Commands tool, as explained in the Wing documentation on
-[pep8 formatting](https://wingware.com/doc/edit/pep8). The detailed procedure is:
+_Black_ can be integrated into many editors with plugins. They let you run _Black_ on
+your code with the ease of doing it in your editor. To get started using _Black_ in your
+editor of choice, please see
+[editor_integration](https://github.com/psf/black/blob/master/docs/editor_integration.md).
-1. Install `black`.
-
-```console
-$ pip install black
-```
-
-2. Make sure it runs from the command line, e.g.
-
-```console
-$ black --help
-```
-
-3. In Wing IDE, activate the **OS Commands** panel and define the command **black** to
- execute black on the currently selected file:
-
-- Use the Tools -> OS Commands menu selection
-- click on **+** in **OS Commands** -> New: Command line..
- - Title: black
- - Command Line: black %s
- - I/O Encoding: Use Default
- - Key Binding: F1
- - [x] Raise OS Commands when executed
- - [x] Auto-save files before execution
- - [x] Line mode
-
-4. Select a file in the editor and press **F1** , or whatever key binding you selected
- in step 3, to reformat the file.
-
-### Vim
-
-Commands and shortcuts:
-
-- `: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.
-
-Configuration:
-
-- `g:black_fast` (defaults to `0`)
-- `g:black_linelength` (defaults to `88`)
-- `g:black_skip_string_normalization` (defaults to `0`)
-- `g:black_virtualenv` (defaults to `~/.vim/black` or `~/.local/share/nvim/black`)
-
-To install with [vim-plug](https://github.com/junegunn/vim-plug):
-
-```
-Plug 'psf/black'
-```
-
-or with [Vundle](https://github.com/VundleVim/Vundle.vim):
-
-```
-Plugin 'psf/black'
-```
-
-or you can copy the plugin from
-[plugin/black.vim](https://github.com/psf/black/tree/master/plugin/black.vim).
-
-```
-mkdir -p ~/.vim/pack/python/start/black/plugin
-curl https://raw.githubusercontent.com/psf/black/master/plugin/black.vim -o ~/.vim/pack/python/start/black/plugin/black.vim
-```
-
-Let me know if this requires any changes to work with Vim 8's builtin `packadd`, or
-Pathogen, and so on.
-
-This plugin **requires Vim 7.0+ built with Python 3.6+ support**. It needs Python 3.6 to
-be able to run _Black_ inside the Vim process which is much faster than calling an
-external command.
-
-On first run, the plugin creates its own virtualenv using the right Python version and
-automatically installs _Black_. You can upgrade it later by calling `:BlackUpgrade` and
-restarting Vim.
-
-If you need to do anything special to make your virtualenv work and install _Black_ (for
-example you want to run a version from master), create a virtualenv manually and point
-`g:black_virtualenv` to it. The plugin will use it.
-
-To run _Black_ on save, add the following line to `.vimrc` or `init.vim`:
-
-```
-autocmd BufWritePre *.py execute ':Black'
-```
-
-To run _Black_ on a key press (e.g. F9 below), add this:
-
-```
-nnoremap :Black
-```
-
-**How to get Vim with Python 3.6?** On Ubuntu 17.10 Vim comes with Python 3.6 by
-default. On macOS with Homebrew run: `brew install vim`. When building Vim from source,
-use: `./configure --enable-python3interp=yes`. There's many guides online how to do
-this.
-
-### Visual Studio Code
-
-Use the
-[Python extension](https://marketplace.visualstudio.com/items?itemName=ms-python.python)
-([instructions](https://code.visualstudio.com/docs/python/editing#_formatting)).
-
-### SublimeText 3
-
-Use [sublack plugin](https://github.com/jgirardet/sublack).
-
-### 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).
-
-### Kakoune
-
-Add the following hook to your kakrc, then run black with `:format`.
-
-```
-hook global WinSetOption filetype=python %{
- set-option window formatcmd 'black -q -'
-}
-```
-
-### Thonny
-
-Use [Thonny-black-code-format](https://github.com/Franccisco/thonny-black-code-format).
-
-### Other editors
-
-Other editors will require external contributions.
-
-Patches welcome! ⨠ð° â¨
-
-Any tool that can pipe code through _Black_ using its stdio mode (just
-[use `-` as the file name](https://www.tldp.org/LDP/abs/html/special-chars.html#DASHREF2)).
-The formatted code will be returned on stdout (unless `--check` was passed). _Black_
-will still emit messages on stderr but that shouldn't affect your use case.
-
-This can be used for example with PyCharm's or IntelliJ's
-[File Watchers](https://www.jetbrains.com/help/pycharm/file-watchers.html).
+Patches are welcome for editors without an editor integration or plugin! More
+information can be found in
+[editor_integration](https://github.com/psf/black/blob/master/docs/editor_integration.md#other-editors).
## blackd
-`blackd` is a small HTTP server that exposes _Black_'s functionality over a simple
+`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
+Black process every time you want to blacken a file. Please refer to
+[blackd](https://github.com/psf/black/blob/master/docs/blackd.md) to get the ball
+rolling.
-`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.
+## black-primer
-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.
+`black-primer` is a tool built for CI (and humans) to have _Black_ `--check` a number of
+(configured in `primer.json`) Git accessible projects in parallel.
+[black_primer](https://github.com/psf/black/blob/master/docs/black_primer.md) has more
+information regarding its usage and configuration.
-`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.
-```
-
-There is no official blackd client tool (yet!). You can test that blackd is working
-using `curl`:
-
-```
-blackd --bind-port 9090 & # or let blackd choose a port
-curl -s -XPOST "localhost:9090" -d "print('valid')"
-```
-
-### 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`.
-- `X-Diff`: corresponds to the `--diff` command line flag. If present, a diff of the
- formats will be output.
-
-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.
-
-The response headers include a `X-Black-Version` header containing the version of
-_Black_.
+(A PR adding Mercurial support will be accepted.)
## Version control integration
@@ -890,10 +372,10 @@ Use [pre-commit](https://pre-commit.com/). Once you
```yaml
repos:
- repo: https://github.com/psf/black
- rev: stable
+ rev: 20.8b1 # Replace by any tag/version: https://github.com/psf/black/tags
hooks:
- id: black
- language_version: python3.6
+ language_version: python3 # Should be a command that runs python3.6+
```
Then run `pre-commit install` and you're ready to go.
@@ -905,9 +387,27 @@ for your project. See _Black_'s own
example.
If you're already using Python 3.7, switch the `language_version` accordingly. Finally,
-`stable` is a tag that is pinned to the latest release on PyPI. If you'd rather run on
+`stable` is a branch that tracks the latest release on PyPI. If you'd rather run on
master, this is also an option.
+## GitHub Actions
+
+Create a file named `.github/workflows/black.yml` inside your repository with:
+
+```yaml
+name: Lint
+
+on: [push, pull_request]
+
+jobs:
+ lint:
+ runs-on: ubuntu-latest
+ steps:
+ - uses: actions/checkout@v2
+ - uses: actions/setup-python@v2
+ - uses: psf/black@stable
+```
+
## Ignoring unmodified files
_Black_ remembers files it has already formatted, unless the `--diff` flag is used or
@@ -934,8 +434,10 @@ then write the above files to `.cache/black//`.
The following notable open-source projects trust _Black_ with enforcing a consistent
code style: pytest, tox, Pyramid, Django Channels, Hypothesis, attrs, SQLAlchemy,
-Poetry, PyPA applications (Warehouse, Pipenv, virtualenv), pandas, Pillow, every Datadog
-Agent Integration, Home Assistant.
+Poetry, PyPA applications (Warehouse, Bandersnatch, Pipenv, virtualenv), pandas, Pillow,
+every Datadog Agent Integration, Home Assistant.
+
+The following organizations use _Black_: Facebook, Dropbox, Mozilla, Quora.
Are we missing anyone? Let us know.
@@ -956,7 +458,7 @@ Twisted and CPython:
> At least the name is good.
**Kenneth Reitz**, creator of [`requests`](http://python-requests.org/) and
-[`pipenv`](https://docs.pipenv.org/):
+[`pipenv`](https://readthedocs.org/projects/pipenv/):
> This vastly improves the formatting of our code. Thanks a ton!
@@ -964,7 +466,7 @@ Twisted and CPython:
Use the badge in your project's README.md:
-```markdown
+```md
[](https://github.com/psf/black)
```
@@ -994,7 +496,14 @@ other hand, if your answer is "because I don't like a particular formatting" the
not ready to embrace _Black_ yet. Such changes are unlikely to get accepted. You can
still try but prepare to be disappointed.
-More details can be found in [CONTRIBUTING](CONTRIBUTING.md).
+More details can be found in
+[CONTRIBUTING](https://github.com/psf/black/blob/master/CONTRIBUTING.md).
+
+## Change log
+
+The log's become rather long. It moved to its own file.
+
+See [CHANGES](https://github.com/psf/black/blob/master/CHANGES.md).
## Authors
@@ -1003,73 +512,180 @@ Glued together by [Åukasz Langa](mailto:lukasz@langa.pl).
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).
+[Mika Naylor](mailto:mail@autophagy.io),
+[Zsolt Dollenstein](mailto:zsol.zsol@gmail.com), and
+[Cooper Lees](mailto:me@cooperlees.com).
Multiple contributions by:
-- [Abdur-Rahmaan Janhangeer](mailto:cryptolabour@gmail.com)
+- [Abdur-Rahmaan Janhangeer](mailto:arj.python@gmail.com)
- [Adam Johnson](mailto:me@adamj.eu)
+- [Adam Williamson](mailto:adamw@happyassassin.net)
- [Alexander Huynh](mailto:github@grande.coffee)
+- [Alex Vandiver](mailto:github@chmrr.net)
+- [Allan Simon](mailto:allan.simon@supinfo.com)
+- Anders-Petter Ljungquist
- [Andrew Thorp](mailto:andrew.thorp.dev@gmail.com)
+- [Andrew Zhou](mailto:andrewfzhou@gmail.com)
- [Andrey](mailto:dyuuus@yandex.ru)
- [Andy Freeland](mailto:andy@andyfreeland.net)
- [Anthony Sottile](mailto:asottile@umich.edu)
- [Arjaan Buijk](mailto:arjaan.buijk@gmail.com)
+- [Arnav Borbornah](mailto:arnavborborah11@gmail.com)
- [Artem Malyshev](mailto:proofit404@gmail.com)
- [Asger Hautop Drewsen](mailto:asgerdrewsen@gmail.com)
- [Augie Fackler](mailto:raf@durin42.com)
- [Aviskar KC](mailto:aviskarkc10@gmail.com)
+- Batuhan TaÅkaya
+- [Benjamin Wohlwend](mailto:bw@piquadrat.ch)
- [Benjamin Woodruff](mailto:github@benjam.info)
+- [Bharat Raghunathan](mailto:bharatraghunthan9767@gmail.com)
- [Brandt Bucher](mailto:brandtbucher@gmail.com)
+- [Brett Cannon](mailto:brett@python.org)
+- [Bryan Bugyi](mailto:bryan.bugyi@rutgers.edu)
+- [Bryan Forbes](mailto:bryan@reigndropsfall.net)
+- [Calum Lind](mailto:calumlind@gmail.com)
+- [Charles](mailto:peacech@gmail.com)
- Charles Reid
+- [Christian Clauss](mailto:cclauss@bluewin.ch)
- [Christian Heimes](mailto:christian@python.org)
- [Chuck Wooters](mailto:chuck.wooters@microsoft.com)
+- [Chris Rose](mailto:offline@offby1.net)
+- Codey Oxley
+- [Cong](mailto:congusbongus@gmail.com)
- [Cooper Ry Lees](mailto:me@cooperlees.com)
+- [Dan Davison](mailto:dandavison7@gmail.com)
- [Daniel Hahler](mailto:github@thequod.de)
- [Daniel M. Capella](mailto:polycitizen@gmail.com)
- Daniele Esposti
+- [David Hotham](mailto:david.hotham@metaswitch.com)
+- [David Lukes](mailto:dafydd.lukes@gmail.com)
+- [David Szotten](mailto:davidszotten@gmail.com)
+- [Denis Laxalde](mailto:denis@laxalde.org)
+- [Douglas Thor](mailto:dthor@transphormusa.com)
- dylanjblack
- [Eli Treuherz](mailto:eli@treuherz.com)
+- [Emil Hessman](mailto:emil@hessman.se)
+- [Felix Kohlgrüber](mailto:felix.kohlgrueber@gmail.com)
- [Florent Thiery](mailto:fthiery@gmail.com)
+- Francisco
+- [Giacomo Tagliabue](mailto:giacomo.tag@gmail.com)
+- [Greg Gandenberger](mailto:ggandenberger@shoprunner.com)
+- [Gregory P. Smith](mailto:greg@krypto.org)
+- Gustavo Camargo
- hauntsaninja
+- [Hadi Alqattan](mailto:alqattanhadizaki@gmail.com)
+- [Heaford](mailto:dan@heaford.com)
+- [Hugo Barrera](mailto::hugo@barrera.io)
- Hugo van Kemenade
+- [Hynek Schlawack](mailto:hs@ox.cx)
- [Ivan KataniÄ](mailto:ivan.katanic@gmail.com)
+- [Jakub Kadlubiec](mailto:jakub.kadlubiec@skyscanner.net)
+- [Jakub Warczarek](mailto:jakub.warczarek@gmail.com)
+- [Jan Hnátek](mailto:jan.hnatek@gmail.com)
- [Jason Fried](mailto:me@jasonfried.info)
+- [Jason Friedland](mailto:jason@friedland.id.au)
- [jgirardet](mailto:ijkl@netc.fr)
+- Jim Brännlund
+- [Jimmy Jia](mailto:tesrin@gmail.com)
- [Joe Antonakakis](mailto:jma353@cornell.edu)
- [Jon Dufresne](mailto:jon.dufresne@gmail.com)
- [Jonas Obrist](mailto:ojiidotch@gmail.com)
+- [Jonty Wareing](mailto:jonty@jonty.co.uk)
+- [Jose Nazario](mailto:jose.monkey.org@gmail.com)
+- [Joseph Larson](mailto:larson.joseph@gmail.com)
- [Josh Bode](mailto:joshbode@fastmail.com)
+- [Josh Holland](mailto:anowlcalledjosh@gmail.com)
+- [José Padilla](mailto:jpadilla@webapplicate.com)
- [Juan Luis Cano RodrÃguez](mailto:hello@juanlu.space)
+- [kaiix](mailto:kvn.hou@gmail.com)
- [Katie McLaughlin](mailto:katie@glasnt.com)
+- Katrin Leinweber
+- [Keith Smiley](mailto:keithbsmiley@gmail.com)
+- [Kenyon Ralph](mailto:kenyon@kenyonralph.com)
+- [Kevin Kirsche](mailto:Kev.Kirsche+GitHub@gmail.com)
+- [Kyle Hausmann](mailto:kyle.hausmann@gmail.com)
+- [Kyle Sunden](mailto:sunden@wisc.edu)
- Lawrence Chan
- [Linus Groh](mailto:mail@linusgroh.de)
+- [Loren Carvalho](mailto:comradeloren@gmail.com)
- [Luka Sterbic](mailto:luka.sterbic@gmail.com)
+- [LukasDrude](mailto:mail@lukas-drude.de)
+- Mahmoud Hossam
- Mariatta
- [Matt VanEseltine](mailto:vaneseltine@gmail.com)
+- [Matthew Clapp](mailto:itsayellow+dev@gmail.com)
+- [Matthew Walster](mailto:matthew@walster.org)
+- Max Smolens
+- [Michael Aquilina](mailto:michaelaquilina@gmail.com)
- [Michael Flaxman](mailto:michael.flaxman@gmail.com)
- [Michael J. Sullivan](mailto:sully@msully.net)
- [Michael McClimon](mailto:michael@mcclimon.org)
- [Miguel Gaiowski](mailto:miggaiowski@gmail.com)
- [Mike](mailto:roshi@fedoraproject.org)
+- [mikehoyio](mailto:mikehoy@gmail.com)
- [Min ho Kim](mailto:minho42@gmail.com)
- [Miroslav Shubernetskiy](mailto:miroslav@miki725.com)
+- MomIsBestFriend
+- [Nathan Goldbaum](mailto:ngoldbau@illinois.edu)
+- [Nathan Hunt](mailto:neighthan.hunt@gmail.com)
- [Neraste](mailto:neraste.herr10@gmail.com)
+- [Nikolaus Waxweiler](mailto:madigens@gmail.com)
- [Ofek Lev](mailto:ofekmeister@gmail.com)
- [Osaetin Daniel](mailto:osaetindaniel@gmail.com)
+- [otstrel](mailto:otstrel@gmail.com)
- [Pablo Galindo](mailto:Pablogsal@gmail.com)
+- [Paul Ganssle](mailto:p.ganssle@gmail.com)
+- [Paul Meinhardt](mailto:mnhrdt@gmail.com)
- [Peter Bengtsson](mailto:mail@peterbe.com)
+- [Peter Grayson](mailto:pete@jpgrayson.net)
+- [Peter Stensmyr](mailto:peter.stensmyr@gmail.com)
- pmacosta
+- [Quentin Pradet](mailto:quentin@pradet.me)
+- [Ralf Schmitt](mailto:ralf@systemexit.de)
+- [Ramón Valles](mailto:mroutis@protonmail.com)
+- [Richard Fearn](mailto:richardfearn@gmail.com)
+- Richard Si
- [Rishikesh Jha](mailto:rishijha424@gmail.com)
+- [Rupert Bedford](mailto:rupert@rupertb.com)
+- Russell Davis
+- [Rémi Verschelde](mailto:rverschelde@gmail.com)
+- [Sami Salonen](mailto:sakki@iki.fi)
+- [Samuel Cormier-Iijima](mailto:samuel@cormier-iijima.com)
+- [Sanket Dasgupta](mailto:sanketdasgupta@gmail.com)
+- Sergi
+- [Scott Stevenson](mailto:scott@stevenson.io)
+- Shantanu
+- [shaoran](mailto:shaoran@sakuranohana.org)
+- [Shinya Fujino](mailto:shf0811@gmail.com)
+- springstan
- [Stavros Korokithakis](mailto:hi@stavros.io)
- [Stephen Rosen](mailto:sirosen@globus.org)
+- [Steven M. Vascellaro](mailto:S.Vascellaro@gmail.com)
- [Sunil Kapil](mailto:snlkapil@gmail.com)
+- [Sébastien Eustace](mailto:sebastien.eustace@gmail.com)
+- [Tal Amuyal](mailto:TalAmuyal@gmail.com)
+- [Terrance](mailto:git@terrance.allofti.me)
- [Thom Lu](mailto:thomas.c.lu@gmail.com)
+- [Thomas Grainger](mailto:tagrain@gmail.com)
+- [Tim Gates](mailto:tim.gates@iress.com)
+- [Tim Swast](mailto:swast@google.com)
+- [Timo](mailto:timo_tk@hotmail.com)
+- Toby Fleming
- [Tom Christie](mailto:tom@tomchristie.com)
+- [Tony Narlock](mailto:tony@git-pull.com)
+- [Tsuyoshi Hombashi](mailto:tsuyoshi.hombashi@gmail.com)
+- [Tushar Chandra](mailto:tusharchandra2018@u.northwestern.edu)
- [Tzu-ping Chung](mailto:uranusjr@gmail.com)
- [Utsav Shah](mailto:ukshah2@illinois.edu)
+- utsav-dbx
- vezeli
+- [Ville Skyttä](mailto:ville.skytta@iki.fi)
- [Vishwas B Sharma](mailto:sharma.vishwas88@gmail.com)
+- [Vlad Emelianov](mailto:volshebnyi@gmail.com)
+- [williamfzc](mailto:178894043@qq.com)
+- [wouter bolsterlee](mailto:wouter@bolsterl.ee)
+- Yazdan
- [Yngve Høiseth](mailto:yngve@hoiseth.net)
- [Yurii Karabas](mailto:1998uriyyo@gmail.com)
+- [Zac Hatfield-Dodds](mailto:zac@zhd.dev)