X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/cfb003f51c89802b5bca29018fde62c4501a8940..e94bda11c366818d24f864ae03abf076e8f5a297:/README.md?ds=inline diff --git a/README.md b/README.md index 3099059..e192826 100644 --- a/README.md +++ b/README.md @@ -3,10 +3,10 @@
@@ -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, @@ -274,6 +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 @@ -327,10 +332,84 @@ interesting cases: - `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. +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 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 + +PEP 484 describes the syntax for type hints in Python. One of the +use cases for typing is providing type annotations for modules which +cannot contain them directly (they might be written in C, or they might +be third-party, or their implementation may be overly dynamic, and so on). + +To solve this, [stub files with the `.pyi` file +extension](https://www.python.org/dev/peps/pep-0484/#stub-files) can be +used to describe typing information for an external module. Those stub +files omit the implementation of classes and functions they +describe, instead they only contain the structure of the file (listing +globals, functions, and classes with their members). The recommended +code style for those files is more terse than PEP 8: + +* prefer `...` on the same line as the class/function signature; +* avoid vertical whitespace between consecutive module-level functions, + names, or methods and fields within a single class; +* use a single blank line between top-level class definitions, or none + if the classes are very small. + +*Black* enforces the above rules. There are additional guidelines for +formatting `.pyi` file that are not enforced yet but might be in +a future version of the formatter: + +* all function bodies should be empty (contain `...` instead of the body); +* do not use docstrings; +* prefer `...` over `pass`; +* for arguments with a default, use `...` instead of the actual default; +* avoid using string literals in type annotations, stub files support + forward references natively (like Python 3.7 code with `from __future__ + import annotations`); +* use variable annotations instead of type comments, even for stubs that + target older versions of Python; +* for arguments that default to `None`, use `Optional[]` explicitly; +* use `float` instead of `Union[int, float]`. ## Editor integration @@ -409,7 +488,7 @@ 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. @@ -429,6 +508,10 @@ Use [joslarson.black-vscode](https://marketplace.visualstudio.com/items?itemName Use [sublack plugin](https://github.com/jgirardet/sublack). +### IPython Notebook Magic + +Use [blackcellmagic](https://github.com/csurfer/blackcellmagic). + ### Other editors Atom/Nuclide integration is planned by the author, others will @@ -538,15 +621,55 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md). ### 18.5a0 (unreleased) +* call chains are now formatted according to the [fluent interfaces](https://en.wikipedia.org/wiki/Fluent_interface) style (#67) + * 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) + +* 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 + on Python 3.6+ only code and Python 2.7+ code with the `unicode_literals` + future import (#188, #198, #199) + +* 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 (#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 + 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. + +* 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 + ### 18.4a4 @@ -745,7 +868,9 @@ Multiple contributions by: * [Eli Treuherz](mailto:eli.treuherz@cgi.com) * Hugo van Kemenade * [Ivan Katanić](mailto:ivan.katanic@gmail.com) +* [Jelle Zijlstra](mailto:jelle.zijlstra@gmail.com) * [Jonas Obrist](mailto:ojiidotch@gmail.com) +* [Miguel Gaiowski](mailto:miggaiowski@gmail.com) * [Osaetin Daniel](mailto:osaetindaniel@gmail.com) * [Sunil Kapil](mailto:snlkapil@gmail.com) * [Vishwas B Sharma](mailto:sharma.vishwas88@gmail.com)