X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/60a8333857e796a897b3aeeea990bcfa0dacffab..6a01b764195e9ddd655c63a5c110e4a6e71a035e:/README.md?ds=inline diff --git a/README.md b/README.md index 38622cd..3f62eec 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

@@ -14,7 +14,7 @@ *Black* is the uncompromising Python code formatter. By using it, you -agree to cease control over minutiae of hand-formatting. In return, +agree to cede control over minutiae of hand-formatting. In return, *Black* gives you speed, determinism, and freedom from `pycodestyle` nagging about formatting. You will save time and mental energy for more important matters. @@ -74,7 +74,7 @@ Options: * 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 occured (or `--check` was +* exits with code 0 unless an internal error occurred (or `--check` was used). @@ -106,9 +106,9 @@ the same effect, as a courtesy for straddling code. *Black* ignores previous formatting and applies uniform horizontal and vertical whitespace to your code. The rules for horizontal -whitespace are pretty obvious and 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. +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, @@ -176,6 +176,14 @@ 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. + ### Line length @@ -218,10 +226,7 @@ bother you if you overdo it by a few km/h". *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. One exception is control flow statements: *Black* will -always emit an extra empty line after ``return``, ``raise``, ``break``, -``continue``, and ``yield``. This is to make changes in control flow -more prominent to readers of your code. +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 @@ -230,11 +235,9 @@ 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 put those empty lines also -between the function definition and any standalone comments that -immediately precede the given function. If you want to comment on the -entire function, use a docstring or put a leading comment in the function -body. +after module-level functions. *Black* will not put empty lines between +function/class definitions and standalone comments that immediately precede +the given function/class. ### Trailing commas @@ -271,6 +274,11 @@ keep it. 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 @@ -289,6 +297,51 @@ 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 + +*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. Otherwise, the parentheses are always added. + ## Editor integration @@ -297,6 +350,36 @@ and let *Black* handle the transformation. Use [proofit404/blacken](https://github.com/proofit404/blacken). +### PyCharm + +1. Install `black`. + + $ pip install black + +2. Locate your `black` installation folder. + + On MacOS / Linux / BSD: + + $ which black + /usr/local/bin/black # possible location + + On Windows: + + $ where black + %LocalAppData%\Programs\Python\Python36-32\Scripts\black.exe # possible location + +3. Open External tools in PyCharm with `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: + - 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`. + + ### Vim Commands and shortcuts: @@ -311,9 +394,21 @@ Configuration: * `g:black_linelength` (defaults to `88`) * `g:black_virtualenv` (defaults to `~/.vim/black`) -To install, copy the plugin from [vim/plugin/black.vim](https://github.com/ambv/black/tree/master/vim/plugin/black.vim). +To install with [vim-plug](https://github.com/junegunn/vim-plug): + +``` +Plug 'ambv/black', +``` + +or with [Vundle](https://github.com/VundleVim/Vundle.vim): + +``` +Plugin 'ambv/black' +``` + +or you can copy the plugin from [plugin/black.vim](https://github.com/ambv/black/tree/master/plugin/black.vim). Let me know if this requires any changes to work with Vim 8's builtin -`packadd`, or Pathogen, or Vundle, and so on. +`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 @@ -324,7 +419,7 @@ 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), just +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. @@ -340,6 +435,13 @@ to do this. Use [joslarson.black-vscode](https://marketplace.visualstudio.com/items?itemName=joslarson.black-vscode). +### SublimeText 3 + +Use [sublack plugin](https://github.com/jgirardet/sublack). + +### IPython Notebook Magic + +Use [blackcellmagic](https://github.com/csurfer/blackcellmagic). ### Other editors @@ -379,6 +481,20 @@ the line length if you really need to. If you're already using Python 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 +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\\AppData\Local\black\black\Cache\\cache..pickle` +* macOS: `/Users//Library/Caches/black//cache..pickle` +* Linux: `/home//.cache/black//cache..pickle` + + ## Testimonials **Dusty Phillips**, [writer](https://smile.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=dusty+phillips): @@ -418,8 +534,8 @@ MIT ## Contributing to Black -In terms of inspiration, *Black* is about as configurable as *gofmt* and -*rustfmt* are. This is deliberate. +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 @@ -434,16 +550,95 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md). ## Change Log +### 18.5a0 (unreleased) + +* 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) + +* 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) + +* fixed an invalid trailing comma sometimes left in imports (#185) + +* fixed non-deterministic formatting when multiple pairs of removable parentheses + were used (#183) + +* 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. + + +### 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) @@ -569,15 +764,19 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md). Glued together by [Łukasz Langa](mailto:lukasz@langa.pl). Maintained with [Carol Willing](mailto:carolcode@willingconsulting.com), -[Carl Meyer](mailto:carl@oddbird.net), and -[Mika Naylor](mailto:mail@autophagy.io). +[Carl Meyer](mailto:carl@oddbird.net), +[Mika Naylor](mailto:mail@autophagy.io), and +[Zsolt Dollenstein](mailto:zsol.zsol@gmail.com). Multiple contributions by: * [Anthony Sottile](mailto:asottile@umich.edu) * [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) * Hugo van Kemenade * [Ivan Katanić](mailto:ivan.katanic@gmail.com) +* [Jonas Obrist](mailto:ojiidotch@gmail.com) * [Osaetin Daniel](mailto:osaetindaniel@gmail.com) -* [Zsolt Dollenstein](mailto:zsol.zsol@gmail.com) +* [Sunil Kapil](mailto:snlkapil@gmail.com) +* [Vishwas B Sharma](mailto:sharma.vishwas88@gmail.com)