Add CORS support to blackd (#627)

[etc/vim.git] / README.md

diff --git a/README.md b/README.md
index cf9db966016b785e796522787d90d4f07f6bb9b2..7be809371ede219d5d093e408913e75228801287 100644 (file)
--- a/README.md
+++ b/README.md
@@ -6,7 +6,8 @@
 <a href="https://black.readthedocs.io/en/stable/?badge=stable"><img alt="Documentation Status" src="https://readthedocs.org/projects/black/badge/?version=stable"></a>
 <a href="https://coveralls.io/github/ambv/black?branch=master"><img alt="Coverage Status" src="https://coveralls.io/repos/github/ambv/black/badge.svg?branch=master"></a>
 <a href="https://github.com/ambv/black/blob/master/LICENSE"><img alt="License: MIT" src="https://black.readthedocs.io/en/stable/_static/license.svg"></a>
 <a href="https://black.readthedocs.io/en/stable/?badge=stable"><img alt="Documentation Status" src="https://readthedocs.org/projects/black/badge/?version=stable"></a>
 <a href="https://coveralls.io/github/ambv/black?branch=master"><img alt="Coverage Status" src="https://coveralls.io/repos/github/ambv/black/badge.svg?branch=master"></a>
 <a href="https://github.com/ambv/black/blob/master/LICENSE"><img alt="License: MIT" src="https://black.readthedocs.io/en/stable/_static/license.svg"></a>

-<a href="https://pypi.python.org/pypi/black"><img alt="PyPI" src="https://black.readthedocs.io/en/stable/_static/pypi.svg"></a>
+<a href="https://pypi.org/project/black/"><img alt="PyPI" src="https://black.readthedocs.io/en/stable/_static/pypi.svg"></a>
+<a href="https://pepy.tech/project/black"><img alt="Downloads" src="https://pepy.tech/badge/black"></a>

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


@@ -26,16 +27,19 @@ 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).
+

 ---
 
 *Contents:* **[Installation and usage](#installation-and-usage)** |
 ---
 
 *Contents:* **[Installation and usage](#installation-and-usage)** |

-**[The *Black* code style](#the-black-code-style)** |
+**[Code style](#the-black-code-style)** |
+**[pyproject.toml](#pyprojecttoml)** |

 **[Editor integration](#editor-integration)** |
 **[Editor integration](#editor-integration)** |

+**[blackd](#blackd)** |

 **[Version control integration](#version-control-integration)** |
 **[Ignoring unmodified files](#ignoring-unmodified-files)** |
 **[Testimonials](#testimonials)** |
 **[Show your style](#show-your-style)** |
 **[Version control integration](#version-control-integration)** |
 **[Ignoring unmodified files](#ignoring-unmodified-files)** |
 **[Testimonials](#testimonials)** |
 **[Show your style](#show-your-style)** |

-**[License](#license)** |

 **[Contributing](#contributing-to-black)** |
 **[Change Log](#change-log)** |
 **[Authors](#authors)**
 **[Contributing](#contributing-to-black)** |
 **[Change Log](#change-log)** |
 **[Authors](#authors)**


@@ -77,6 +81,8 @@ Options:
                               source on standard input).
   -S, --skip-string-normalization
                               Don't normalize string quotes or prefixes.
                               source on standard input).
   -S, --skip-string-normalization
                               Don't normalize string quotes or prefixes.

+  -N, --skip-numeric-underscore-normalization
+                              Don't normalize underscores in numeric literals.

   --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
   --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


@@ -94,8 +100,8 @@ Options:
                               directories that should be excluded on
                               recursive searches. On Windows, use forward
                               slashes for directories.  [default:
                               directories that should be excluded on
                               recursive searches. On Windows, use forward
                               slashes for directories.  [default:

-                              build/|buck-out/|dist/|_build/|\.git/|\.hg/|
-                              \.mypy_cache/|\.tox/|\.venv/]
+                              build/|buck-out/|dist/|_build/|\.eggs/|\.git/|
+                              \.hg/|\.mypy_cache/|\.nox/|\.tox/|\.venv/]

   -q, --quiet                 Don't emit non-error messages to stderr. Errors
                               are still emitted, silence those with
                               2>/dev/null.
   -q, --quiet                 Don't emit non-error messages to stderr. Errors
                               are still emitted, silence those with
                               2>/dev/null.


@@ -103,6 +109,7 @@ Options:
                               that were not changed or were ignored due to
                               --exclude=.
   --version                   Show the version and exit.
                               that were not changed or were ignored due to
                               --exclude=.
   --version                   Show the version and exit.

+  --config PATH               Read configuration from PATH.

   --help                      Show this message and exit.
 ```
 
   --help                      Show this message and exit.
 ```
 


@@ -136,7 +143,8 @@ original.  This slows it down.  If you're feeling confident, use
 
 *Black* reformats entire files in place.  It is not configurable.  It
 doesn't take previous formatting into account.  It doesn't reformat
 
 *Black* reformats entire files in place.  It is not configurable.  It
 doesn't take previous formatting into account.  It doesn't reformat

-blocks that start with `# fmt: off` and end with `# fmt: on`.  It also
+blocks that start with `# fmt: off` and end with `# fmt: on`. `# fmt: on/off`
+have to be on the same level of indentation. It also

 recognizes [YAPF](https://github.com/google/yapf)'s block comments to
 the same effect, as a courtesy for straddling code.
 
 recognizes [YAPF](https://github.com/google/yapf)'s block comments to
 the same effect, as a courtesy for straddling code.
 


@@ -230,13 +238,13 @@ the following configuration.
 multi_line_output=3
 include_trailing_comma=True
 force_grid_wrap=0
 multi_line_output=3
 include_trailing_comma=True
 force_grid_wrap=0

-combine_as_imports=True
+use_parentheses=True

 line_length=88
 ```
 
 The equivalent command line is:
 ```
 line_length=88
 ```
 
 The equivalent command line is:
 ```

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

 ```
 </details>
 
 ```
 </details>
 


@@ -272,7 +280,8 @@ ignore = E501
 ```
 
 You'll find *Black*'s own .flake8 config file is configured like this.
 ```
 
 You'll find *Black*'s own .flake8 config file is configured like this.

-If you're curious about the reasoning behind B950, Bugbear's documentation
+If you're curious about the reasoning behind B950, 
+[Bugbear's documentation](https://github.com/PyCQA/flake8-bugbear#opinionated-warnings)

 explains it.  The tl;dr is "it's like highway speed limits, we won't
 bother you if you overdo it by a few km/h".
 
 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".
 


@@ -350,8 +359,8 @@ string literals that ended up on the same line (see
 [#26](https://github.com/ambv/black/issues/26) for details).
 
 Why settle on double quotes?  They anticipate apostrophes in English
 [#26](https://github.com/ambv/black/issues/26) for details).
 
 Why settle on double quotes?  They anticipate apostrophes in English

-text.  They match the docstring standard described in PEP 257.  An
-empty string in double quotes (`""`) is impossible to confuse with
+text.  They match the docstring standard described in [PEP 257](https://www.python.org/dev/peps/pep-0257/#what-is-a-docstring).
+An empty string in double quotes (`""`) is impossible to confuse with

 a one double-quote regardless of fonts and syntax highlighting used.
 On top of this, double quotes for strings are consistent with C which
 Python interacts a lot with.
 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.


@@ -367,6 +376,19 @@ 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.
 
 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`. In
+Python 3.6+, *Black* adds underscores to long numeric literals to aid
+readability: `100000000` becomes `100_000_000`.
+
+For regions where numerals are grouped differently (like [India](https://en.wikipedia.org/wiki/Indian_numbering_system)
+and [China](https://en.wikipedia.org/wiki/Chinese_numerals#Whole_numbers)),
+the `-N` or `--skip-numeric-underscore-normalization` command line option
+makes *Black* preserve underscores in numeric literals.

 
 ### Line breaks & binary operators
 
 
 ### Line breaks & binary operators
 


@@ -487,6 +509,101 @@ a future version of the formatter:
 * use `float` instead of `Union[int, float]`.
 
 
 * use `float` instead of `Union[int, float]`.
 
 

+## pyproject.toml
+
+*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.
+
+**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
+py36 = true
+include = '\.pyi?$'
+exclude = '''
+/(
+    \.eggs
+  | \.git
+  | \.hg
+  | \.mypy_cache
+  | \.tox
+  | \.venv
+  | _build
+  | buck-out
+  | build
+  | dist
+
+  # The following are specific to Black, you probably don't want those.
+  | blib2to3
+  | tests/data
+)/
+'''
+```
+
+</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.
+
+

 ## Editor integration
 
 ### Emacs
 ## Editor integration
 
 ### Emacs


@@ -524,17 +641,28 @@ $ where black
     - Name: Black
     - Description: Black is the uncompromising Python code formatter.
     - Program: <install_location_from_step_2>
     - Name: Black
     - Description: Black is the uncompromising Python code formatter.
     - Program: <install_location_from_step_2>

-    - Arguments: $FilePath$
+    - Arguments: `$FilePath$`

 
 5. Format the currently opened file by selecting `Tools -> External Tools -> black`.
     - Alternatively, you can set a keyboard shortcut by navigating to `Preferences -> Keymap -> External Tools -> External Tools - Black`.
 
 
 5. Format the currently opened file by selecting `Tools -> External Tools -> black`.
     - Alternatively, you can set a keyboard shortcut by navigating to `Preferences -> Keymap -> External Tools -> External Tools - Black`.
 

+6. Optionally, run Black on every file save:
+
+    1. Make sure you have the [File Watcher](https://plugins.jetbrains.com/plugin/7177-file-watchers) plugin installed.
+    2. Go to `Preferences -> Tools -> File Watchers` and click `+` to add a new watcher:
+        - Name: Black
+        - File type: Python
+        - Scope: Project Files
+        - Program: <install_location_from_step_2>
+        - Arguments: `$FilePath$`
+        - Output paths to refresh: `$FilePathRelativeToProjectRoot$`
+        - Working directory: `$ProjectFileDir$`

 
 ### Vim
 
 Commands and shortcuts:
 
 
 ### Vim
 
 Commands and shortcuts:
 

-* `,=` or `:Black` to format the entire file (ranges not supported);
+* `:Black` to format the entire file (ranges not supported);

 * `:BlackUpgrade` to upgrade *Black* inside the virtualenv;
 * `:BlackVersion` to get the current version of *Black* inside the
   virtualenv.
 * `:BlackUpgrade` to upgrade *Black* inside the virtualenv;
 * `:BlackVersion` to get the current version of *Black* inside the
   virtualenv.


@@ -542,12 +670,13 @@ Commands and shortcuts:
 Configuration:
 * `g:black_fast` (defaults to `0`)
 * `g:black_linelength` (defaults to `88`)
 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`)
 
 To install with [vim-plug](https://github.com/junegunn/vim-plug):
 
 ```
 * `g:black_virtualenv` (defaults to `~/.vim/black`)
 
 To install with [vim-plug](https://github.com/junegunn/vim-plug):
 
 ```

-Plug 'ambv/black',
+Plug 'ambv/black'

 ```
 
 or with [Vundle](https://github.com/VundleVim/Vundle.vim):
 ```
 
 or with [Vundle](https://github.com/VundleVim/Vundle.vim):


@@ -576,7 +705,7 @@ The plugin will use it.
 To run *Black* on save, add the following line to `.vimrc` or `init.vim`:
 
 ```
 To run *Black* on save, add the following line to `.vimrc` or `init.vim`:
 
 ```

-autocmd BufWritePost *.py execute ':Black'
+autocmd BufWritePre *.py execute ':Black'

 ```
 
 **How to get Vim with Python 3.6?**
 ```
 
 **How to get Vim with Python 3.6?**


@@ -590,8 +719,7 @@ to do this.
 ### Visual Studio Code
 
 Use the [Python extension](https://marketplace.visualstudio.com/items?itemName=ms-python.python)
 ### 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))
-or [joslarson.black-vscode](https://marketplace.visualstudio.com/items?itemName=joslarson.black-vscode).
+([instructions](https://code.visualstudio.com/docs/python/editing#_formatting)).

 
 
 ### SublimeText 3
 
 
 ### SublimeText 3


@@ -599,15 +727,27 @@ or [joslarson.black-vscode](https://marketplace.visualstudio.com/items?itemName=
 Use [sublack plugin](https://github.com/jgirardet/sublack).
 
 
 Use [sublack plugin](https://github.com/jgirardet/sublack).
 
 

-### IPython Notebook Magic
+### Jupyter Notebook Magic

 
 Use [blackcellmagic](https://github.com/csurfer/blackcellmagic).
 
 
 
 Use [blackcellmagic](https://github.com/csurfer/blackcellmagic).
 
 

+### Python Language Server
+
+If your editor supports the [Language Server Protocol](https://langserver.org/)
+(Atom, Sublime Text, Visual Studio Code and many more), you can use
+the [Python Language Server](https://github.com/palantir/python-language-server) with the
+[pyls-black](https://github.com/rupert/pyls-black) plugin.
+
+
+### Atom/Nuclide
+
+Use [python-black](https://atom.io/packages/python-black).
+
+

 ### Other editors
 
 ### Other editors
 

-Atom/Nuclide integration is planned by the author, others will
-require external contributions.
+Other editors will require external contributions.

 
 Patches welcome! ✨ 🍰 ✨
 
 
 Patches welcome! ✨ 🍰 ✨
 


@@ -619,6 +759,78 @@ affect your use case.
 
 This can be used for example with PyCharm's [File Watchers](https://www.jetbrains.com/help/pycharm/file-watchers.html).
 
 
 This can be used for example with PyCharm's [File Watchers](https://www.jetbrains.com/help/pycharm/file-watchers.html).
 

+## blackd
+
+`blackd` is a small HTTP server that exposes *Black*'s functionality over
+a simple protocol. The main benefit of using it is to avoid paying the
+cost of starting up a new *Black* process every time you want to blacken
+a file.
+
+### Usage
+
+`blackd` is not packaged alongside *Black* by default because it has additional
+dependencies. You will need to do `pip install black[d]` to install it.
+
+You can start the server on the default port, binding only to the local interface
+by running `blackd`. You will see a single line mentioning the server's version,
+and the host and port it's listening on. `blackd` will then print an access log
+similar to most web servers on standard output, merged with any exception traces
+caused by invalid formatting requests.
+
+`blackd` provides even less options than *Black*. You can see them by running
+`blackd --help`:
+
+```text
+Usage: blackd [OPTIONS]
+
+Options:
+  --bind-host TEXT                Address to bind the server to.
+  --bind-port INTEGER             Port to listen on
+  --version                       Show the version and exit.
+  -h, --help                      Show this message and exit.
+```
+
+### Protocol
+
+`blackd` only accepts `POST` requests at the `/` path. The body of the request
+should contain the python source code to be formatted, encoded
+according to the `charset` field in the `Content-Type` request header. If no
+`charset` is specified, `blackd` assumes `UTF-8`.
+
+There are a few HTTP headers that control how the source is formatted. These
+correspond to command line flags for *Black*. There is one exception to this:
+`X-Protocol-Version` which if present, should have the value `1`, otherwise the
+request is rejected with `HTTP 501` (Not Implemented).
+
+The headers controlling how code is formatted are:
+
+ - `X-Line-Length`: corresponds to the `--line-length` command line flag.
+ - `X-Skip-String-Normalization`: corresponds to the `--skip-string-normalization`
+    command line flag. If present and its value is not the empty string, no string
+    normalization will be performed.
+ - `X-Skip-Numeric-Underscore-Normalization`: corresponds to the
+    `--skip-numeric-underscore-normalization` command line flag.
+ - `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. If this value represents at least Python 3.6, `blackd` will
+    act as *Black* does when passed the `--py36` command line flag.
+
+If any of these headers are set to invalid values, `blackd` returns a `HTTP 400`
+error response, mentioning the name of the problematic header in the message body.
+
+Apart from the above, `blackd` can produce the following response codes:
+
+ - `HTTP 204`: If the input is already well-formatted. The response body is
+       empty.
+ - `HTTP 200`: If formatting was needed on the input. The response body
+       contains the blackened Python code, and the `Content-Type` header is set
+       accordingly.
+ - `HTTP 400`: If the input contains a syntax error. Details of the error are
+       returned in the response body.
+ - `HTTP 500`: If there was any kind of error while trying to format the input.
+       The response body contains a textual representation of the error.

 
 ## Version control integration
 
 
 ## Version control integration
 


@@ -631,16 +843,18 @@ repos:
     rev: stable
     hooks:
     - id: black
     rev: stable
     hooks:
     - id: black

-      args: [--line-length=88, --safe]

       language_version: python3.6
 ```
 Then run `pre-commit install` and you're ready to go.
 
       language_version: python3.6
 ```
 Then run `pre-commit install` and you're ready to go.
 

-`args` in the above config is optional but shows you how you can change
-the line length if you really need to.  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.
+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`
+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
 
 
 ## Ignoring unmodified files


@@ -651,9 +865,12 @@ location of the file depends on the *Black* version and the system on which *Bla
 is run. The file is non-portable. The standard location on common operating systems
 is:
 
 is run. The file is non-portable. The standard location on common operating systems
 is:
 

-* Windows: `C:\\Users\<username>\AppData\Local\black\black\Cache\<version>\cache.<line-length>.pickle`
-* macOS: `/Users/<username>/Library/Caches/black/<version>/cache.<line-length>.pickle`
-* Linux: `/home/<username>/.cache/black/<version>/cache.<line-length>.pickle`
+* Windows: `C:\\Users\<username>\AppData\Local\black\black\Cache\<version>\cache.<line-length>.<file-mode>.pickle`
+* macOS: `/Users/<username>/Library/Caches/black/<version>/cache.<line-length>.<file-mode>.pickle`
+* Linux: `/home/<username>/.cache/black/<version>/cache.<line-length>.<file-mode>.pickle`
+
+`file-mode` is an int flag that determines whether the file was formatted as 3.6+ only,
+as .pyi, and whether string normalization was omitted.

 
 
 ## Testimonials
 
 
 ## Testimonials


@@ -662,7 +879,7 @@ is:
 
 > *Black* is opinionated so you don't have to be.
 
 
 > *Black* is opinionated so you don't have to be.
 

-**Hynek Schlawack**, [creator of `attrs`](http://www.attrs.org/), core
+**Hynek Schlawack**, [creator of `attrs`](https://www.attrs.org/), core

 developer of Twisted and CPython:
 
 > An auto-formatter that doesn't suck is all I want for Xmas!
 developer of Twisted and CPython:
 
 > An auto-formatter that doesn't suck is all I want for Xmas!


@@ -685,6 +902,12 @@ Use the badge in your project's README.md:
 [![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/ambv/black)
 ```
 
 [![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/ambv/black)
 ```
 

+Using the badge in README.rst:
+```
+.. image:: https://img.shields.io/badge/code%20style-black-000000.svg
+    :target: https://github.com/ambv/black
+```
+

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


@@ -711,6 +934,100 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md).
 
 ## Change Log
 
 
 ## Change Log
 

+### 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)
 ### 18.6b1
 
 * hotfix: don't output human-facing information on stdout (#299)


@@ -954,7 +1271,7 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md).
 ### 18.3a2
 
 * changed positioning of binary operators to occur at beginning of lines
 ### 18.3a2
 
 * changed positioning of binary operators to occur at beginning of lines

-  instead of at the end, following [a recent change to PEP8](https://github.com/python/peps/commit/c59c4376ad233a62ca4b3a6060c81368bd21e85b)
+  instead of at the end, following [a recent change to PEP 8](https://github.com/python/peps/commit/c59c4376ad233a62ca4b3a6060c81368bd21e85b)

   (#21)
 
 * ignore empty bracket pairs while splitting. This avoids very weirdly
   (#21)
 
 * ignore empty bracket pairs while splitting. This avoids very weirdly


@@ -1013,6 +1330,7 @@ Glued together by [Łukasz Langa](mailto:lukasz@langa.pl).
 
 Maintained with [Carol Willing](mailto:carolcode@willingconsulting.com),
 [Carl Meyer](mailto:carl@oddbird.net),
 
 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), and
 [Zsolt Dollenstein](mailto:zsol.zsol@gmail.com).
 


@@ -1021,30 +1339,17 @@ Multiple contributions by:
 * [Artem Malyshev](mailto:proofit404@gmail.com)
 * [Christian Heimes](mailto:christian@python.org)
 * [Daniel M. Capella](mailto:polycitizen@gmail.com)
 * [Artem Malyshev](mailto:proofit404@gmail.com)
 * [Christian Heimes](mailto:christian@python.org)
 * [Daniel M. Capella](mailto:polycitizen@gmail.com)

-* [Eli Treuherz](mailto:eli.treuherz@cgi.com)
+* [Eli Treuherz](mailto:eli@treuherz.com)

 * Hugo van Kemenade
 * [Ivan Katanić](mailto:ivan.katanic@gmail.com)
 * Hugo van Kemenade
 * [Ivan Katanić](mailto:ivan.katanic@gmail.com)

-* [Jelle Zijlstra](mailto:jelle.zijlstra@gmail.com)

 * [Jonas Obrist](mailto:ojiidotch@gmail.com)
 * [Luka Sterbic](mailto:luka.sterbic@gmail.com)
 * [Miguel Gaiowski](mailto:miggaiowski@gmail.com)
 * [Jonas Obrist](mailto:ojiidotch@gmail.com)
 * [Luka Sterbic](mailto:luka.sterbic@gmail.com)
 * [Miguel Gaiowski](mailto:miggaiowski@gmail.com)

+* [Miroslav Shubernetskiy](mailto:miroslav@miki725.com)
+* [Neraste](neraste.herr10@gmail.com)

 * [Osaetin Daniel](mailto:osaetindaniel@gmail.com)
 * [Peter Bengtsson](mailto:mail@peterbe.com)
 * [Stavros Korokithakis](mailto:hi@stavros.io)
 * [Sunil Kapil](mailto:snlkapil@gmail.com)
 * [Vishwas B Sharma](mailto:sharma.vishwas88@gmail.com)
 * [Osaetin Daniel](mailto:osaetindaniel@gmail.com)
 * [Peter Bengtsson](mailto:mail@peterbe.com)
 * [Stavros Korokithakis](mailto:hi@stavros.io)
 * [Sunil Kapil](mailto:snlkapil@gmail.com)
 * [Vishwas B Sharma](mailto:sharma.vishwas88@gmail.com)

-
----
-
-*Contents:*
-**[Installation and Usage](#installation-and-usage)** |
-**[The *Black* code style](#the-black-code-style)** |
-**[Editor integration](#editor-integration)** |
-**[Version control integration](#version-control-integration)** |
-**[Ignoring unmodified files](#ignoring-unmodified-files)** |
-**[Testimonials](#testimonials)** |
-**[Show your style](#show-your-style)** |
-**[License](#license)** |
-**[Contributing](#contributing-to-black)** |
-**[Change Log](#change-log)** |
-**[Authors](#authors)**
+* [Chuck Wooters](mailto:chuck.wooters@microsoft.com)