Fix an embarrassing UnboundLocalError

[etc/vim.git] / README.md

diff --git a/README.md b/README.md
index 38622cd3c7b89e71acf9d8d0a17a7d80dd0d478a..06b732466eb3b305307992f35a23df99cc476956 100644 (file)
--- a/README.md
+++ b/README.md
@@ -289,6 +289,33 @@ 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.
+
+### 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 (...)`
+
+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 +324,36 @@ 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: <install_location_from_step_2>
+    - 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:
@@ -438,6 +495,8 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md).
 
 * 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)
@@ -569,8 +628,9 @@ 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)
@@ -580,4 +640,3 @@ Multiple contributions by:
 * Hugo van Kemenade
 * [Ivan Katanić](mailto:ivan.katanic@gmail.com)
 * [Osaetin Daniel](mailto:osaetindaniel@gmail.com)
-* [Zsolt Dollenstein](mailto:zsol.zsol@gmail.com)