X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/96e68f034197d6060aad876216a0e40e0eac0987..c891c65b6b2de7c257244cc409276b485130c275:/README.md diff --git a/README.md b/README.md index 152ceef..57f3ac2 100644 --- a/README.md +++ b/README.md @@ -78,14 +78,16 @@ 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 +133,13 @@ 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 @@ -176,13 +178,13 @@ 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/). Use +`multi_line_output=3`, `include_trailing_comma=True`, +`force_grid_wrap=0`, and `line_length=88` in your isort config. ### Line length @@ -268,6 +270,7 @@ 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 (`'` @@ -297,6 +300,7 @@ 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 @@ -308,6 +312,7 @@ 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 +326,7 @@ 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 +346,41 @@ 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 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 @@ -472,14 +512,17 @@ 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 Atom/Nuclide integration is planned by the author, others will @@ -587,7 +630,15 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md). ## Change Log -### 18.5a0 (unreleased) +### 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) @@ -619,6 +670,9 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md). * 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 @@ -628,6 +682,9 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md). * 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