**[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)** |
### Numeric literals
-*Black* standardizes most numeric literals to use lowercase letters: `0xab`
+*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
This can be used for example with PyCharm's [File Watchers](https://www.jetbrains.com/help/pycharm/file-watchers.html).
+## blackd
+
+`blackd` is a small HTTP server that exposes *Black*'s functionality over
+a simple protocol. The main benefit of using it is to avoid paying the
+cost of starting up a new *Black* process every time you want to blacken
+a file.
+
+### Usage
+
+`blackd` is not packaged alongside *Black* by default because it has additional
+dependencies. You will need to do `pip install black[d]` to install it.
+
+You can start the server on the default port, binding only to the local interface
+by running `blackd`. You will see a single line mentioning the server's version,
+and the host and port it's listening on. `blackd` will then print an access log
+similar to most web servers on standard output, merged with any exception traces
+caused by invalid formatting requests.
+
+`blackd` provides even less options than *Black*. You can see them by running
+`blackd --help`:
+
+```text
+Usage: blackd [OPTIONS]
+
+Options:
+ --bind-host TEXT Address to bind the server to.
+ --bind-port INTEGER Port to listen on
+ --version Show the version and exit.
+ -h, --help Show this message and exit.
+```
+
+### Protocol
+
+`blackd` only accepts `POST` requests at the `/` path. The body of the request
+should contain the python source code to be formatted, encoded
+according to the `charset` field in the `Content-Type` request header. If no
+`charset` is specified, `blackd` assumes `UTF-8`.
+
+There are a few HTTP headers that control how the source is formatted. These
+correspond to command line flags for *Black*. There is one exception to this:
+`X-Protocol-Version` which if present, should have the value `1`, otherwise the
+request is rejected with `HTTP 501` (Not Implemented).
+
+The headers controlling how code is formatted are:
+
+ - `X-Line-Length`: corresponds to the `--line-length` command line flag.
+ - `X-Skip-String-Normalization`: corresponds to the `--skip-string-normalization`
+ command line flag. If present and its value is not the empty string, no string
+ normalization will be performed.
+ - `X-Fast-Or-Safe`: if set to `fast`, `blackd` will act as *Black* does when
+ passed the `--fast` command line flag.
+ - `X-Python-Variant`: if set to `pyi`, `blackd` will act as *Black* does when
+ passed the `--pyi` command line flag. Otherwise, its value must correspond to
+ a Python version. 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
## Change Log
-### 18.8b0
-
-* adjacent string literals are now correctly split into multiple lines (#463)
+### 18.9b0
* numeric literals are now formatted by *Black* (#452, #461, #464, #469):
* most letters in numeric literals are lowercased (e.g., in `1e10` or `0xab`)
+* added `blackd`, see [its documentation](#blackd) for more info (#349)
+
+* adjacent string literals are now correctly split into multiple lines (#463)
+
* cache is now populated when `--check` is successful for a file which speeds up
consecutive checks of properly formatted unmodified files (#448)
+* code with `_` in numeric literals is recognized as Python 3.6+ (#461)
+
+* 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)
-* note: the Vim plugin stopped registering ``,=`` as a default chord as it turned out
- to be a bad idea (#415)
-
* fixed formatting of lambda expressions with default arguments (#468)
-* *Black* no longer breaks ``async for`` statements up to separate lines (#372)
+* 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)
-* fixed unstable formatting when unpacking big tuples (#267)
### 18.6b4
projects / etc / vim.git / blobdiff