Add a description for the pre-commit hook (#107)

[etc/vim.git] / README.md

diff --git a/README.md b/README.md
index ac4caa19414773bf97caca88a6904f4302e3d0aa..dac918eb905940c0d8027a2587d4934745203e24 100644 (file)
--- a/README.md
+++ b/README.md
@@ -53,13 +53,18 @@ black [OPTIONS] [SRC]...
 
 Options:
   -l, --line-length INTEGER   Where to wrap around.  [default: 88]
-  --check                     Don't write back the files, just return the
+  --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
                               reformatted.  Return code 123 means there was an
                               internal error.
+  --diff                      Don't write the files back, just output a diff
+                              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.
 ```
@@ -159,7 +164,7 @@ def very_important_function(
     debug: bool = False,
 ):
     """Applies `variables` to the `template` and writes to `file`."""
-    with open(file, 'w') as f:
+    with open(file, "w") as f:
         ...
 ```
 
@@ -260,6 +265,30 @@ 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 (`'`
+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
 
@@ -328,6 +357,28 @@ affect your use case.
 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):
@@ -383,11 +434,35 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md).
 
 ## Change Log
 
-### 18.3a5 (unreleased)
+### 18.4a1
+
+* added `--quiet` (#78)
+
+* fixed reporting on `--check` with multiple files (#101, #102)
+
+### 18.4a0
+
+* added `--diff` (#87)
+
+* 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
+  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)
+
+* 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
   lines within functions (#74)
 
@@ -497,5 +572,7 @@ Multiple contributions by:
 * [Daniel M. Capella](mailto:polycitizen@gmail.com)
 * [Eli Treuherz](mailto:eli.treuherz@cgi.com)
 * Hugo van Kemenade
-* [Mika⠙](mailto:mail@autophagy.io)
+* [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)