add more flake8 lints (#2653)

[etc/vim.git] / README.md

diff --git a/README.md b/README.md
index 8dceeacc2d205d2a2e65679073854cfab1cf4b5b..2adf60a783a1cd8c77d0e89010a97ecafa96c122 100644 (file)
--- a/README.md
+++ b/README.md
@@ -1,14 +1,16 @@
-![Black Logo](https://raw.githubusercontent.com/psf/black/master/docs/_static/logo2-readme.png)
+![Black Logo](https://raw.githubusercontent.com/psf/black/main/docs/_static/logo2-readme.png)

 
 <h2 align="center">The Uncompromising Code Formatter</h2>
 
 <p align="center">
 
 <h2 align="center">The Uncompromising Code Formatter</h2>
 
 <p align="center">

-<a href="https://travis-ci.com/psf/black"><img alt="Build Status" src="https://travis-ci.com/psf/black.svg?branch=master"></a>
+<a href="https://github.com/psf/black/actions"><img alt="Actions Status" src="https://github.com/psf/black/workflows/Test/badge.svg"></a>
+<a href="https://github.com/psf/black/actions"><img alt="Actions Status" src="https://github.com/psf/black/workflows/Primer/badge.svg"></a>

 <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://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/psf/black?branch=master"><img alt="Coverage Status" src="https://coveralls.io/repos/github/psf/black/badge.svg?branch=master"></a>
-<a href="https://github.com/psf/black/blob/master/LICENSE"><img alt="License: MIT" src="https://black.readthedocs.io/en/stable/_static/license.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://coveralls.io/github/psf/black?branch=main"><img alt="Coverage Status" src="https://coveralls.io/repos/github/psf/black/badge.svg?branch=main"></a>
+<a href="https://github.com/psf/black/blob/main/LICENSE"><img alt="License: MIT" src="https://black.readthedocs.io/en/stable/_static/license.svg"></a>
+<a href="https://pypi.org/project/black/"><img alt="PyPI" src="https://img.shields.io/pypi/v/black"></a>

 <a href="https://pepy.tech/project/black"><img alt="Downloads" src="https://pepy.tech/badge/black"></a>
 <a href="https://pepy.tech/project/black"><img alt="Downloads" src="https://pepy.tech/badge/black"></a>

+<a href="https://anaconda.org/conda-forge/black/"><img alt="conda-forge" src="https://img.shields.io/conda/dn/conda-forge/black.svg?label=conda-forge"></a>

 <a href="https://github.com/psf/black"><img alt="Code style: black" src="https://img.shields.io/badge/code%20style-black-000000.svg"></a>
 </p>
 
 <a href="https://github.com/psf/black"><img alt="Code style: black" src="https://img.shields.io/badge/code%20style-black-000000.svg"></a>
 </p>
 


@@ -24,19 +26,12 @@ becomes transparent after a while and you can focus on the content instead.
 
 _Black_ makes code review faster by producing the smallest diffs possible.
 
 
 _Black_ makes code review faster by producing the smallest diffs possible.
 

-Try it out now using the [Black Playground](https://black.now.sh). Watch the
+Try it out now using the [Black Playground](https://black.vercel.app). Watch the

 [PyCon 2019 talk](https://youtu.be/esZLCuWs_2Y) to learn more.
 
 ---
 
 [PyCon 2019 talk](https://youtu.be/esZLCuWs_2Y) to learn more.
 
 ---
 

-_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)** | **[Used by](#used-by)** |
-**[Testimonials](#testimonials)** | **[Show your style](#show-your-style)** |
-**[Contributing](#contributing-to-black)** | **[Change Log](#change-log)** |
-**[Authors](#authors)**
+**[Read the documentation on ReadTheDocs!](https://black.readthedocs.io/en/stable)**

 
 ---
 
 
 ---
 


@@ -44,886 +39,118 @@ _Contents:_ **[Installation and usage](#installation-and-usage)** |
 
 ### Installation
 
 
 ### Installation
 

-_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.
+_Black_ can be installed by running `pip install black`. It requires Python 3.6.2+ to
+run. If you want to format Python 2 code as well, install with
+`pip install black[python2]`. If you want to format Jupyter Notebooks, install with
+`pip install black[jupyter]`.
+
+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:
 
 
 ### Usage
 
 To get started right away with sensible defaults:
 

-```
+```sh

 black {source_file_or_directory}
 ```
 
 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]...
-
-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]
-                                  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
-                                  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.
+You can run _Black_ as a package if running it as a script doesn't work:
+
+```sh
+python -m black {source_file_or_directory}

 ```
 
 ```
 

-_Black_ is a well-behaved Unix-style command-line tool:
+Further information can be found in our docs:

 
 

-- it does nothing if no sources are passed to it;
-- it will read from standard input and write to standard output if `-` is used as the
-  filename;
-- it only outputs messages to users on standard error;
-- exits with code 0 unless an internal error occurred (or `--check` was used).
+- [Usage and Configuration](https://black.readthedocs.io/en/stable/usage_and_configuration/index.html)

 
 ### NOTE: This is a beta product
 
 
 ### 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.
-
-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`.
+_Black_ is already [successfully used](https://github.com/psf/black#used-by) by many
+projects, small and big. Black has a comprehensive test suite, with efficient parallel
+tests, and our own auto formatting and parallel Continuous Integration runner. However,
+_Black_ is still beta. 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.
+
+Also, as a safety measure which slows down processing, _Black_ will check that the
+reformatted code still produces a valid AST that is effectively equivalent to the
+original (see the
+[Pragmatism](https://black.readthedocs.io/en/stable/the_black_code_style/current_style.html#ast-before-and-after-formatting)
+section for details). If you're feeling confident, use `--fast`.

 
 ## The _Black_ code style
 
 
 ## 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:
-
-j = [1,
-     2,
-     3,
-]
-
-# out:
-
-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:
-
-ImportantClass.important_method(exc, limit, lookup_lines, capture_locals, extra_argument)
-
-# 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:
-        ...
-```
-
-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).
+_Black_ is a PEP 8 compliant opinionated formatter. _Black_ reformats entire files in
+place. Style configuration options are deliberately limited and rarely added. It doesn't
+take previous formatting into account (see [Pragmatism](#pragmatism) for exceptions).

 
 

-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.
+Our documentation covers the current _Black_ code style, but planned changes to it are
+also documented. They're both worth taking a look:

 
 

-<details>
-<summary>A compatible `.isort.cfg`</summary>
+- [The _Black_ Code Style: Current style](https://black.readthedocs.io/en/stable/the_black_code_style/current_style.html)
+- [The _Black_ Code Style: Future style](https://black.readthedocs.io/en/stable/the_black_code_style/future_style.html)

 
 

-```
-[settings]
-multi_line_output=3
-include_trailing_comma=True
-force_grid_wrap=0
-use_parentheses=True
-line_length=88
-```
+Please refer to this document before submitting an issue. What seems like a bug might be
+intended behaviour.

 
 

-The equivalent command line is:
+### Pragmatism

 
 

-```
-$ isort --multi-line=3 --trailing-comma --force-grid-wrap=0 --use-parentheses --line-width=88 [ file.py ]
-```
+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.

 
 

-</details>
-
-### 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 _Black_ code style: Pragmatism](https://black.readthedocs.io/en/stable/the_black_code_style/current_style.html#pragmatism)

 
 

-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".
-
-### Empty lines
-
-_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.
-
-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 just like with the document
+above. 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)
-```
-
-### 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()
-    )
-```
-
-### 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]`.
-
-## pyproject.toml
+## Configuration

 
 _Black_ is able to read project-specific default values for its command line options
 from a `pyproject.toml` file. This is especially useful for specifying custom
 
 _Black_ is able to read project-specific default values for its command line options
 from a `pyproject.toml` file. This is especially useful for specifying custom

-`--include` and `--exclude` patterns for your project.
+`--include` and `--exclude`/`--force-exclude`/`--extend-exclude` patterns for your
+project.

 
 

-**Pro-tip**: If you're asking yourself "Do I need to configure anything?" the answer is
-"No". _Black_ is all about sensible defaults.
-
-### What on Earth is a `pyproject.toml` file?
-
-[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
-[Flit](https://flit.readthedocs.io/en/latest/) it can fully replace the need for
-`setup.py` and `setup.cfg` files.
-
-### Where _Black_ looks for the file
-
-By default _Black_ looks for `pyproject.toml` starting from the common base directory of
-all files and directories passed on the command line. If it's not there, it looks in
-parent directories. It stops looking when it finds the file, or a `.git` directory, or a
-`.hg` directory, or the root of the file system, whichever comes first.
-
-If you're formatting standard input, _Black_ will look for configuration starting from
-the current working directory.
-
-You can also explicitly specify the path to a particular file that you want with
-`--config`. In this situation _Black_ will not look for any other file.
-
-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
-
-As the file extension suggests, `pyproject.toml` is a
-[TOML](https://github.com/toml-lang/toml) file. It contains separate sections for
-different tools. _Black_ is using the `[tool.black]` section. The option keys are the
-same as long names of options on the command line.
-
-Note that you have to use single-quoted strings in TOML for regular expressions. It's
-the equivalent of r-strings in Python. Multiline strings are treated as verbose regular
-expressions by Black. Use `[ ]` to denote a significant space character.
-
-<details>
-<summary>Example `pyproject.toml`</summary>
-
-```toml
-[tool.black]
-line-length = 88
-target-version = ['py37']
-include = '\.pyi?$'
-exclude = '''
-
-(
-  /(
-      \.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
-)
-'''
-```
-
-</details>
-
-### Lookup hierarchy
-
-Command-line options have defaults that you can see in `--help`. A `pyproject.toml` can
-override those defaults. Finally, options provided by the user on the command line
-override both.
-
-_Black_ will only ever use one `pyproject.toml` file during an entire run. It doesn't
-look for multiple files, and doesn't compose configuration from different levels of the
-file hierarchy.
+You can find more details in our documentation:

 
 

-## Editor integration
+- [The basics: Configuration via a file](https://black.readthedocs.io/en/stable/usage_and_configuration/the_basics.html#configuration-via-a-file)

 
 

-### 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
-```
+And if you're looking for more general configuration documentation:

 
 

-2. Locate your `black` installation folder.
+- [Usage and Configuration](https://black.readthedocs.io/en/stable/usage_and_configuration/index.html)

 
 

-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: <install_location_from_step_2>
-   - 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: <install_location_from_step_2>
-      - 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:
-
-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 <F9> :Black<CR>
-```
-
-**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 --with-python3`. 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  -'
-}
-```
-
-### Other editors
-
-Other editors will require external contributions.
-
-Patches welcome! ✨ 🍰 ✨
-
-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).
-
-## 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.
-```
-
-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`.
-
-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_.
-
-## Version control integration
-
-Use [pre-commit](https://pre-commit.com/). Once you
-[have it installed](https://pre-commit.com/#install), add this to the
-`.pre-commit-config.yaml` in your repository:
-
-```yaml
-repos:
-  - repo: https://github.com/psf/black
-    rev: stable
-    hooks:
-      - id: black
-        language_version: python3.6
-```
-
-Then run `pre-commit install` and you're ready to go.
-
-Avoid using `args` in the hook. Instead, store necessary configuration in
-`pyproject.toml` so that editors and command-line usage of Black all behave consistently
-for your project. See _Black_'s own [pyproject.toml](/pyproject.toml) for an 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
-master, this is also an option.
-
-## Ignoring unmodified files
-
-_Black_ remembers files it has already formatted, unless the `--diff` flag is used or
-code is passed via standard input. This information is stored per-user. The exact
-location of the file depends on the _Black_ version and the system on which _Black_ 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>.<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.
-
-To override the location of these files on macOS or Linux, set the environment variable
-`XDG_CACHE_HOME` to your preferred location. For example, if you want to put the cache
-in the directory you're running _Black_ from, set `XDG_CACHE_HOME=.cache`. _Black_ will
-then write the above files to `.cache/black/<version>/`.
+**Pro-tip**: If you're asking yourself "Do I need to configure anything?" the answer is
+"No". _Black_ is all about sensible defaults. Applying those defaults will have your
+code in compliance with many other _Black_ formatted projects.

 
 ## Used by
 
 The following notable open-source projects trust _Black_ with enforcing a consistent
 code style: pytest, tox, Pyramid, Django Channels, Hypothesis, attrs, SQLAlchemy,
 
 ## Used by
 
 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.
+Poetry, PyPA applications (Warehouse, Bandersnatch, Pipenv, virtualenv), pandas, Pillow,
+Twisted, LocalStack, every Datadog Agent Integration, Home Assistant, Zulip, Kedro, and
+many more.
+
+The following organizations use _Black_: Facebook, Dropbox, KeepTruckin, Mozilla, Quora,
+Duolingo, QuantumBlack, Tesla.

 
 Are we missing anyone? Let us know.
 
 ## Testimonials
 
 
 Are we missing anyone? Let us know.
 
 ## Testimonials
 

+**Mike Bayer**, [author of `SQLAlchemy`](https://www.sqlalchemy.org/):
+
+> I can't think of any single tool in my entire programming career that has given me a
+> bigger productivity increase by its introduction. I can now do refactorings in about
+> 1% of the keystrokes that it would have taken me previously when we had no way for
+> code to format itself.
+

 **Dusty Phillips**,
 [writer](https://smile.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=dusty+phillips):
 
 **Dusty Phillips**,
 [writer](https://smile.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=dusty+phillips):
 


@@ -939,7 +166,7 @@ Twisted and CPython:
 > At least the name is good.
 
 **Kenneth Reitz**, creator of [`requests`](http://python-requests.org/) and
 > 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!
 
 
 > This vastly improves the formatting of our code. Thanks a ton!
 


@@ -947,7 +174,7 @@ Twisted and CPython:
 
 Use the badge in your project's README.md:
 
 
 Use the badge in your project's README.md:
 

-```markdown
+```md

 [![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/psf/black)
 ```
 
 [![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/psf/black)
 ```
 


@@ -965,531 +192,39 @@ Looks like this:
 
 MIT
 
 
 MIT
 

-## Contributing to _Black_
-
-In terms of inspiration, _Black_ is about as configurable as _gofmt_. This is
-deliberate.
-
-Bug reports and fixes are always welcome! However, before you suggest a new feature or
-configuration knob, ask yourself why you want it. If it enables better integration with
-some workflow, fixes an inconsistency, speeds things up, and so on - go for it! On the
-other hand, if your answer is "because I don't like a particular formatting" then you're
-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).
-
-## Change Log
-
-### 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)
-
-- _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)
+## Contributing

 
 

-- _Black_ no longer fails on comments in from-imports (#671)
+Welcome! Happy to see you willing to make the project better. You can get started by
+reading this:

 
 

-- _Black_ no longer fails when the file starts with a backslash (#922)
+- [Contributing: The basics](https://black.readthedocs.io/en/latest/contributing/the_basics.html)

 
 

-- _Black_ no longer merges regular comments with type comments (#1027)
+You can also take a look at the rest of the contributing docs or talk with the
+developers:

 
 

-- _Black_ no longer splits long lines that contain type comments (#997)
+- [Contributing documentation](https://black.readthedocs.io/en/latest/contributing/index.html)
+- [Chat on Discord](https://discord.gg/RtVdv86PrH)

 
 

-- removed unnecessary parentheses around `yield` expressions (#834)
+## Change log

 
 

-- added parentheses around long tuples in unpacking assignments (#832)
+The log has become rather long. It moved to its own file.

 
 

-- added parentheses around complex powers when they are prefixed by a unary operator
-  (#646)
+See [CHANGES](https://black.readthedocs.io/en/latest/change_log.html).

 
 

-- 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)
-
-### 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)
+## Authors

 
 

-### 18.3a0
+The author list is quite long nowadays, so it lives in its own file.

 
 

-- first published version, Happy 🍰 Day 2018!
+See [AUTHORS.md](./AUTHORS.md)

 
 

-- alpha quality
+## Code of Conduct

 
 

-- date-versioned (see: https://calver.org/)
+Everyone participating in the _Black_ project, and in particular in the issue tracker,
+pull requests, and social media activity, is expected to treat other people with respect
+and more generally to follow the guidelines articulated in the
+[Python Community Code of Conduct](https://www.python.org/psf/codeofconduct/).

 
 

-## Authors
+At the same time, humor is encouraged. In fact, basic familiarity with Monty Python's
+Flying Circus is expected. We are not savages.

 
 

-Glued together by [Łukasz 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).
-
-Multiple contributions by:
-
-- [Abdur-Rahmaan Janhangeer](mailto:cryptolabour@gmail.com)
-- [Adam Johnson](mailto:me@adamj.eu)
-- [Alexander Huynh](mailto:github@grande.coffee)
-- [Andrew Thorp](mailto:andrew.thorp.dev@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)
-- [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)
-- [Benjamin Woodruff](mailto:github@benjam.info)
-- [Brandt Bucher](mailto:brandtbucher@gmail.com)
-- Charles Reid
-- [Christian Heimes](mailto:christian@python.org)
-- [Chuck Wooters](mailto:chuck.wooters@microsoft.com)
-- [Daniel Hahler](mailto:github@thequod.de)
-- [Daniel M. Capella](mailto:polycitizen@gmail.com)
-- Daniele Esposti
-- dylanjblack
-- [Eli Treuherz](mailto:eli@treuherz.com)
-- [Florent Thiery](mailto:fthiery@gmail.com)
-- hauntsaninja
-- Hugo van Kemenade
-- [Ivan Katanić](mailto:ivan.katanic@gmail.com)
-- [Jason Fried](mailto:me@jasonfried.info)
-- [jgirardet](mailto:ijkl@netc.fr)
-- [Joe Antonakakis](mailto:jma353@cornell.edu)
-- [Jon Dufresne](mailto:jon.dufresne@gmail.com)
-- [Jonas Obrist](mailto:ojiidotch@gmail.com)
-- [Josh Bode](mailto:joshbode@fastmail.com)
-- [Juan Luis Cano Rodríguez](mailto:hello@juanlu.space)
-- [Katie McLaughlin](mailto:katie@glasnt.com)
-- [Linus Groh](mailto:mail@linusgroh.de)
-- [Luka Sterbic](mailto:luka.sterbic@gmail.com)
-- Mariatta
-- [Matt VanEseltine](mailto:vaneseltine@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)
-- [Min ho Kim](mailto:minho42@gmail.com)
-- [Miroslav Shubernetskiy](mailto:miroslav@miki725.com)
-- [Neraste](mailto:neraste.herr10@gmail.com)
-- [Ofek Lev](mailto:ofekmeister@gmail.com)
-- [Osaetin Daniel](mailto:osaetindaniel@gmail.com)
-- [Pablo Galindo](mailto:Pablogsal@gmail.com)
-- [Peter Bengtsson](mailto:mail@peterbe.com)
-- pmacosta
-- [Rishikesh Jha](mailto:rishijha424@gmail.com)
-- [Stavros Korokithakis](mailto:hi@stavros.io)
-- [Stephen Rosen](mailto:sirosen@globus.org)
-- [Sunil Kapil](mailto:snlkapil@gmail.com)
-- [Thom Lu](mailto:thomas.c.lu@gmail.com)
-- [Tom Christie](mailto:tom@tomchristie.com)
-- [Tzu-ping Chung](mailto:uranusjr@gmail.com)
-- [Utsav Shah](mailto:ukshah2@illinois.edu)
-- vezeli
-- [Vishwas B Sharma](mailto:sharma.vishwas88@gmail.com)
-- [Yngve Høiseth](mailto:yngve@hoiseth.net)
-- [Yurii Karabas](mailto:1998uriyyo@gmail.com)
+And if you _really_ need to slap somebody, do it with a fish while dancing.