Document black-jupyter hook (#3650)

[etc/vim.git] / docs / the_black_code_style / current_style.md

diff --git a/docs/the_black_code_style/current_style.md b/docs/the_black_code_style/current_style.md
index 5085b0017d9b59bb2d32c45ff4c0fc5dfed12e8e..83f8785cc554bef9fab9d187cb64b20824bfe4ec 100644 (file)
--- a/docs/the_black_code_style/current_style.md
+++ b/docs/the_black_code_style/current_style.md
@@ -85,6 +85,19 @@ def very_important_function(
         ...
 ```
 
+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](../guides/using_black_with_other_tools.md#isort) with the ready-made `black`
+profile or manual configuration.
+
+You might have noticed that closing brackets are always dedented and that a trailing
+comma is always added. Such formatting produces smaller diffs; when you add or remove an
+element, it's always just one line. Also, having the closing bracket dedented provides a
+clear delimiter 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).
+
 (labels/why-no-backslashes)=
 
 _Black_ prefers parentheses over backslashes, and will remove backslashes if found.
@@ -127,19 +140,6 @@ If you're reaching for backslashes, that's a clear signal that you can do better
 slightly refactor your code. I hope some of the examples above show you that there are
 many ways in which you can do it.
 
-You might have noticed that closing brackets are always dedented and that a trailing
-comma is always added. Such formatting produces smaller diffs; when you add or remove an
-element, it's always just one line. Also, having the closing bracket dedented provides a
-clear delimiter 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 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](../guides/using_black_with_other_tools.md#isort) with the ready-made `black`
-profile or manual configuration.
-
 ### Line length
 
 You probably noticed the peculiar default line length. _Black_ defaults to 88 characters
@@ -194,7 +194,45 @@ that in-function vertical whitespace should only be used sparingly.
 _Black_ will allow single empty lines inside functions, and single and double empty
 lines on module level left by the original editors, except when they're within
 parenthesized expressions. Since such expressions are always reformatted to fit minimal
-space, this whitespace is lost.
+space, this whitespace is lost. The other exception is that it will remove any empty
+lines immediately following a statement that introduces a new indentation level.
+
+```python
+# in:
+
+def foo():
+
+    print("All the newlines above me should be deleted!")
+
+
+if condition:
+
+    print("No newline above me!")
+
+    print("There is a newline above me, and that's OK!")
+
+
+class Point:
+
+    x: int
+    y: int
+
+# out:
+
+def foo():
+    print("All the newlines above me should be deleted!")
+
+
+if condition:
+    print("No newline above me!")
+
+    print("There is a newline above me, and that's OK!")
+
+
+class Point:
+    x: int
+    y: int
+```
 
 It will also insert proper spacing before and after function definitions. It's one line
 before and after inner functions and two lines before and after module-level functions
@@ -406,6 +444,11 @@ file that are not enforced yet but might be in a future version of the formatter
 - use variable annotations instead of type comments, even for stubs that target older
   versions of Python.
 
+### Line endings
+
+_Black_ will normalize line endings (`\n` or `\r\n`) based on the first line ending of
+the file.
+
 ## Pragmatism
 
 Early versions of _Black_ used to be absolutist in some respects. They took after its
@@ -452,15 +495,15 @@ the latter are treated as true raw strings with no special semantics.
 
 ### AST before and after formatting
 
-When run with `--safe`, _Black_ checks that the code before and after is semantically
-equivalent. This check is done by comparing the AST of the source with the AST of the
-target. There are three limited cases in which the AST does differ:
+When run with `--safe` (the default), _Black_ checks that the code before and after is
+semantically equivalent. This check is done by comparing the AST of the source with the
+AST of the target. There are three limited cases in which the AST does differ:
 
 1. _Black_ cleans up leading and trailing whitespace of docstrings, re-indenting them if
    needed. It's been one of the most popular user-reported features for the formatter to
    fix whitespace issues with docstrings. While the result is technically an AST
-   difference, due to the various possibilities of forming docstrings, all realtime use
-   of docstrings that we're aware of sanitizes indentation and leading/trailing
+   difference, due to the various possibilities of forming docstrings, all real-world
+   uses of docstrings that we're aware of sanitize indentation and leading/trailing
    whitespace anyway.
 
 1. _Black_ manages optional parentheses for some statements. In the case of the `del`