From 97060a4f18341cdd7deb908cfd6bcf0fd7f302c8 Mon Sep 17 00:00:00 2001
From: Richard Si <63936253+ichard26@users.noreply.github.com>
Date: Sat, 16 May 2020 05:21:31 -0400
Subject: [PATCH] Expand docs about slice formatting (#1418)

Black will apply no spaces around ':' operators for 'simple' expresssions
, but will apply extra space around ':' operators for 'complex' expressions.
Black treats anything more than variable names as 'complex', but this isn't
noted in the Black documentation. Which leads to a few issues on the GitHub
issue tracker that all report inconsistent spacing around ':' operators.
---
 README.md | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 5bf6f06..405eae6 100644
--- a/README.md
+++ b/README.md
@@ -481,9 +481,12 @@ PEP 8
 [recommends](https://www.python.org/dev/peps/pep-0008/#whitespace-in-expressions-and-statements)
 to treat `:` in slices as a binary operator with the lowest priority, and to leave an
 equal amount of space on either side, except if a parameter is omitted (e.g.
-`ham[1 + 1 :]`). It also states that for extended slices, both `:` operators have to
-have the same amount of spacing, except if a parameter is omitted (`ham[1 + 1 ::]`).
-_Black_ enforces these rules consistently.
+`ham[1 + 1 :]`). It recommends no spaces around `:` operators for "simple expressions"
+(`ham[lower:upper]`), and extra space for "complex expressions"
+(`ham[lower : upper + offset]`). _Black_ treats anything more than variable names as
+"complex" (`ham[lower : upper + 1]`). It also states that for extended slices, both `:`
+operators have to have the same amount of spacing, except if a parameter is omitted
+(`ham[1 + 1 ::]`). _Black_ enforces these rules consistently.
 
 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
-- 
2.39.2