Add CORS support to blackd (#627)

[etc/vim.git] / README.md

diff --git a/README.md b/README.md
index 96a24a1eb4ac1d63534ebf8a9cec06d45599a15a..7be809371ede219d5d093e408913e75228801287 100644 (file)
--- a/README.md
+++ b/README.md
@@ -6,8 +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="http://pepy.tech/project/black"><img alt="Downloads" src="http://pepy.tech/badge/black"></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>
 


@@ -35,6 +35,7 @@ Try it out now using the [Black Playground](https://black.now.sh).
 **[Code style](#the-black-code-style)** |
 **[pyproject.toml](#pyprojecttoml)** |
 **[Editor integration](#editor-integration)** |
 **[Code style](#the-black-code-style)** |
 **[pyproject.toml](#pyprojecttoml)** |
 **[Editor integration](#editor-integration)** |

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

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


@@ -80,6 +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


@@ -97,8 +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.


@@ -140,7 +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.
 


@@ -234,13 +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>
 


@@ -276,7 +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".
 


@@ -354,8 +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.


@@ -371,6 +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
 


@@ -530,6 +548,8 @@ other file.
 If you're running with `--verbose`, you will see a blue message if
 a file was found and used.
 
 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
 
 
 ### Configuration format
 


@@ -553,7 +573,8 @@ py36 = true
 include = '\.pyi?$'
 exclude = '''
 /(
 include = '\.pyi?$'
 exclude = '''
 /(

-    \.git
+    \.eggs
+  | \.git

   | \.hg
   | \.mypy_cache
   | \.tox
   | \.hg
   | \.mypy_cache
   | \.tox


@@ -655,7 +676,7 @@ Configuration:
 To install with [vim-plug](https://github.com/junegunn/vim-plug):
 
 ```
 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):


@@ -706,7 +727,7 @@ Use the [Python extension](https://marketplace.visualstudio.com/items?itemName=m
 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).
 


@@ -721,7 +742,7 @@ the [Python Language Server](https://github.com/palantir/python-language-server)
 
 ### Atom/Nuclide
 
 
 ### Atom/Nuclide
 

-Use [atom-black](https://github.com/hauntsaninja/atom-black).
+Use [python-black](https://atom.io/packages/python-black).

 
 
 ### Other editors
 
 
 ### Other editors


@@ -738,6 +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
 


@@ -786,7 +879,7 @@ as .pyi, and whether string normalization was omitted.
 
 > *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!


@@ -841,18 +934,46 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md).
 
 ## Change Log
 
 
 ## Change Log
 

-### 18.8b0
+### 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`)

 
 

-* numeric literals are now normalized to include `_` separators on Python 3.6+ code
-  (#452)
+* 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)
 
 
 * 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 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)
 
 * note: the Vim plugin stopped registering ``,=`` as a default chord as it turned out
   to be a bad idea (#415)
 


@@ -1218,7 +1339,7 @@ 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)
 * [Jonas Obrist](mailto:ojiidotch@gmail.com)
 * Hugo van Kemenade
 * [Ivan Katanić](mailto:ivan.katanic@gmail.com)
 * [Jonas Obrist](mailto:ojiidotch@gmail.com)


@@ -1231,3 +1352,4 @@ Multiple contributions by:
 * [Stavros Korokithakis](mailto:hi@stavros.io)
 * [Sunil Kapil](mailto:snlkapil@gmail.com)
 * [Vishwas B Sharma](mailto:sharma.vishwas88@gmail.com)
 * [Stavros Korokithakis](mailto:hi@stavros.io)
 * [Sunil Kapil](mailto:snlkapil@gmail.com)
 * [Vishwas B Sharma](mailto:sharma.vishwas88@gmail.com)

+* [Chuck Wooters](mailto:chuck.wooters@microsoft.com)