for each file on stdout.
--fast / --safe If --fast given, skip temporary sanity checks.
[default: --safe]
+ -q, --quiet Don't emit non-error messages to stderr. Errors
+ are still emitted, silence those with
+ 2>/dev/null.
--version Show the version and exit.
--help Show this message and exit.
```
### Strings
-*Black* prefers double quotes (`"` and `"""`), but only if this does not
-result in more escaping. It will remove escape sequences as necessary as
-part of moving to the other type of quote. This applies to all kinds of
-prefixed strings, including *raw-strings* (`r""`), *byte literals* (`b""`),
-and *formatted strings* (`f""`). The approach above strikes a good balance
-between consistency and legibility.
+*Black* prefers double quotes (`"` and `"""`) over single quotes (`'`
+and `'''`). It will replace the latter with the former as long as it
+does not result in more backslash escapes than before.
+
+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
+string literals that ended up on the same line (see
+[#26](https://github.com/ambv/black/issues/26) for details).
+
+Why settle on double quotes? They anticipate apostrophes in English
+text. They match the docstring standard described in PEP 257. An
+empty string in double quotes (`""`) is impossible to confuse with
+a one double-quote regardless of fonts and syntax highlighting used.
+On top of this, double quotes for strings are consistent with C which
+Python interacts a lot with.
+
+On certain keyboard layouts like US English, typing single quotes is
+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.
## Editor integration
This can be used for example with PyCharm's [File Watchers](https://www.jetbrains.com/help/pycharm/file-watchers.html).
+## Version control integration
+
+Use [pre-commit](https://pre-commit.com/). Once you [have it
+installed](https://pre-commit.com/#install), add this to the
+`.pre-commit-config.yaml` in your repository:
+```yaml
+repos:
+- repo: https://github.com/ambv/black
+ rev: stable
+ hooks:
+ - id: black
+ args: [--line-length=88, --safe]
+ python_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.
+
## Testimonials
**Dusty Phillips**, [writer](https://smile.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=dusty+phillips):
## Change Log
-### 18.3a5 (unreleased)
+### 18.4a1
+
+* added `--quiet` (#78)
+
+* 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)
-* add line breaks before all delimiters, except in cases like commas, to better
- comply with PEP 8 (#73)
+* add line breaks before all delimiters, except in cases like commas, to
+ better comply with PEP 8 (#73)
+
+* standardize string literals to use double quotes (almost) everywhere
+ (#75)
* fixed handling of standalone comments within nested bracketed
expressions; Black will no longer produce super long lines or put all
* 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)
+
* when CTRL+C is pressed while formatting many files, Black no longer
freaks out with a flurry of asyncio-related exceptions
and [Carl Meyer](mailto:carl@oddbird.net).
Multiple contributions by:
+* [Anthony Sottile](mailto:asottile@umich.edu)
* [Artem Malyshev](mailto:proofit404@gmail.com)
* [Daniel M. Capella](mailto:polycitizen@gmail.com)
* [Eli Treuherz](mailto:eli.treuherz@cgi.com)
* Hugo van Kemenade
+* [Ivan Katanić](mailto:ivan.katanic@gmail.com)
* [Mika Naylor](mailto:mail@autophagy.io)
* [Osaetin Daniel](mailto:osaetindaniel@gmail.com)
+* [Zsolt Dollenstein](mailto:zsol.zsol@gmail.com)