X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/2b3206dc2326e6e2d6edca8c5f8cef682963eee7..c50b10749369b0175994c4da0c78876c71ae75dc:/README.md?ds=sidebyside diff --git a/README.md b/README.md index 6c99fd3..c34e578 100644 --- a/README.md +++ b/README.md @@ -3,10 +3,10 @@

Build Status -Documentation Status +Documentation Status Coverage Status -License: MIT -PyPI +License: MIT +PyPI Code style: black

@@ -26,8 +26,23 @@ content instead. *Black* makes code review faster by producing the smallest diffs possible. +--- -## Installation and Usage +*Contents:* **[Installation and usage](#installation-and-usage)** | +**[Code style](#the-black-code-style)** | +**[pyproject.toml](#pyprojecttoml)** | +**[Editor integration](#editor-integration)** | +**[Version control integration](#version-control-integration)** | +**[Ignoring unmodified files](#ignoring-unmodified-files)** | +**[Testimonials](#testimonials)** | +**[Show your style](#show-your-style)** | +**[Contributing](#contributing-to-black)** | +**[Change Log](#change-log)** | +**[Authors](#authors)** + +--- + +## Installation and usage ### Installation @@ -45,7 +60,7 @@ black {source_file_or_directory} ### Command line options -Black doesn't provide many options. You can list them by running +*Black* doesn't provide many options. You can list them by running `black --help`: ```text @@ -53,6 +68,15 @@ black [OPTIONS] [SRC]... Options: -l, --line-length INTEGER Where to wrap around. [default: 88] + --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. [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 @@ -62,10 +86,24 @@ Options: 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. On Windows, use forward + slashes for directories. [default: \.pyi?$] + --exclude TEXT A regular expression that matches files and + 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/] -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. --help Show this message and exit. ``` @@ -78,14 +116,16 @@ Options: used). -### NOTE: This is an early pre-release +### NOTE: This is a beta product -*Black* can already successfully format itself and the standard library. +*Black* is already successfully used by several 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 -"Alpha" trove classifier, as well as by the "a" in the version number. +"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**. +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 @@ -131,13 +171,13 @@ brackets and put that in a separate indented line. ```py3 # in: -l = [[n for n in list_bosses()], [n for n in list_employees()]] +TracebackException.from_exception(exc, limit, lookup_lines, capture_locals) # out: -l = [ - [n for n in list_bosses()], [n for n in list_employees()] -] +TracebackException.from_exception( + exc, limit, lookup_lines, capture_locals +) ``` If that still doesn't fit the bill, it will decompose the internal @@ -176,14 +216,30 @@ 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). -If a line of "from" imports cannot fit in the allotted length, it's always split -into one per line. Imports tend to change often and this minimizes diffs, as well -as enables readers of code to easily find which commit introduced a particular -import. This exception also makes *Black* compatible with -[isort](https://pypi.org/p/isort/). Use `multi_line_output=3`, -`include_trailing_comma=True`, `force_grid_wrap=0`, and `line_length=88` in your -isort config. +If a data structure literal (tuple, list, set, dict) or a line of "from" +imports cannot fit in the allotted length, it's always split into one +element per line. This minimizes diffs as well as enables readers of +code to find which commit introduced a particular entry. This also +makes *Black* compatible with [isort](https://pypi.org/p/isort/) with +the following configuration. + +
+A compatible `.isort.cfg` +``` +[settings] +multi_line_output=3 +include_trailing_comma=True +force_grid_wrap=0 +combine_as_imports=True +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 ] +``` +
### Line length @@ -235,9 +291,17 @@ 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. *Black* will not put empty lines between -function/class definitions and standalone comments that immediately precede -the given function/class. +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. + +*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 @@ -268,6 +332,7 @@ 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 (`'` @@ -297,7 +362,14 @@ 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. -### Line Breaks & Binary Operators +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. + + +### 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 @@ -308,6 +380,7 @@ 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) @@ -321,6 +394,7 @@ 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 @@ -340,7 +414,41 @@ interesting cases: 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. Otherwise, the parentheses are always added. +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 @@ -380,6 +488,98 @@ a future version of the formatter: * 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. + + +### 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. + +
+Example `pyproject.toml` + +```toml +[tool.black] +line-length = 88 +py36 = true +include = '\.pyi?$' +exclude = ''' +/( + \.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 +)/ +''' +``` + +
+ +### 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 @@ -391,19 +591,25 @@ Use [proofit404/blacken](https://github.com/proofit404/blacken). 1. Install `black`. - $ pip install black +```console +$ pip install black +``` 2. Locate your `black` installation folder. - On MacOS / Linux / BSD: + On macOS / Linux / BSD: - $ which black - /usr/local/bin/black # possible location +```console +$ which black +/usr/local/bin/black # possible location +``` On Windows: - $ where black - %LocalAppData%\Programs\Python\Python36-32\Scripts\black.exe # possible location +```console +$ where black +%LocalAppData%\Programs\Python\Python36-32\Scripts\black.exe # possible location +``` 3. Open External tools in PyCharm with `File -> Settings -> Tools -> External Tools`. @@ -414,7 +620,7 @@ Use [proofit404/blacken](https://github.com/proofit404/blacken). - 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`. + - Alternatively, you can set a keyboard shortcut by navigating to `Preferences -> Keymap -> External Tools -> External Tools - Black`. ### Vim @@ -429,6 +635,7 @@ Commands and shortcuts: 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): @@ -460,9 +667,15 @@ 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' +``` + **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`. +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. @@ -470,16 +683,28 @@ to do this. ### Visual Studio Code -Use [joslarson.black-vscode](https://marketplace.visualstudio.com/items?itemName=joslarson.black-vscode). +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). + ### IPython 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. + + ### Other editors Atom/Nuclide integration is planned by the author, others will @@ -488,7 +713,7 @@ require external contributions. Patches welcome! ✨ 🍰 ✨ Any tool that can pipe code through *Black* using its stdio mode (just -[use `-` as the file name](http://www.tldp.org/LDP/abs/html/special-chars.html#DASHREF2)). +[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. @@ -507,23 +732,25 @@ repos: rev: stable hooks: - id: black - args: [--line-length=88, --safe] - python_version: python3.6 + 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 `python_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 non-modified files -*Black* remembers files it already formatted, unless the `--diff` flag is used or +## 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 +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: @@ -536,7 +763,7 @@ is: **Dusty Phillips**, [writer](https://smile.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=dusty+phillips): -> 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 developer of Twisted and CPython: @@ -561,6 +788,12 @@ 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) ``` +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) @@ -569,7 +802,7 @@ Looks like this: [![Code style: black](https://img.shields.io/badge/code%20style MIT -## Contributing to Black +## Contributing to *Black* In terms of inspiration, *Black* is about as configurable as *gofmt*. This is deliberate. @@ -587,7 +820,127 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md). ## Change Log -### 18.5a0 (unreleased) +### 18.8b0 + +* fix parsing of `__future__` imports with renames (#389) + +### 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) @@ -597,6 +950,9 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md). * 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 @@ -606,14 +962,19 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md). * 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 + 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 @@ -621,6 +982,11 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md). 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 @@ -639,10 +1005,10 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md). * 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 +* *Black* no longer enforces putting empty lines behind control flow statements (#90) -* Black now splits imports like "Mode 3 + trailing comma" of isort (#127) +* *Black* now splits imports like "Mode 3 + trailing comma" of isort (#127) * fixed comment indentation when a standalone comment closes a block (#16, #32) @@ -695,16 +1061,16 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md). (#75) * fixed handling of standalone comments within nested bracketed - expressions; Black will no longer produce super long lines or put all + 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) + would cause *Black* to not emit the rest of the file (#95) -* when CTRL+C is pressed while formatting many files, Black no longer +* 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 @@ -751,7 +1117,7 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md). ### 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 @@ -823,7 +1189,11 @@ Multiple contributions by: * [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) +* [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)