yapf 0.28.0 now removes blank line between class docstring and first function

[gyscos]

Given this code:

class Foo:
    """Cool class"""

    def bar(self):
        """Cool function"""
        pass

yapf 0.28.0 now removes the line after """Cool class""", which makes pydocstyle complain with:

D204: 1 blank line required after class docstring

Yapf 0.27.0 keeps this blank line.

[gwelymernans]

Which style are you using? With --style pep8 it removes the blank line. There was a recent patch to change how the style is processed (9e3cb7196a). Could that be causing this?

[gyscos]

Yes, it's using the default style pep8:

$ echo '
class Foo:
    """Cool class"""

    def bar(self):
        """Cool function"""
        pass
' | yapf

Though it seems to differ from the actual pep8 recommendation (yapf up to version 0.27.0 was correctly preserving the blank line).

[gwelymernans]

If I set BLANK_LINE_BEFORE_NESTED_CLASS_OR_DEF to True, several of the PEP8 tests fail. E.g.:

Diff:
--- actual
+++ expected
@@ -1,5 +1,4 @@
 class Foo:
-
     def foo(self):
         foofoofoofoofoofoofoofoo('foofoofoofoofoo', {
             'foo': 'foo',

Is having the blank line in this situation correct?

[gyscos]

In this test case there is no docstring. I think the blank line should only be here when there is a docstring.

[gwelymernans]

Would that also apply to nested functions?

def _():
  """some docstring here"""

  def nested():
    pass

[gyscos]

In this case I think PEP8 says there should not be a blank line.

Actually reading https://www.python.org/dev/peps/pep-0008/#blank-lines it seems that even without docstring, methods in a class should be surrounded by a single blank line, so there probably _should_ be a line between class Foo: and def foo(self):.

[gyscos]

https://www.python.org/dev/peps/pep-0257/#multi-line-docstrings

Insert a blank line after all docstrings (one-line or multi-line) that document a class -- generally speaking, the class's methods are separated from each other by a single blank line, and the docstring needs to be offset from the first method by a blank line.

[gwelymernans]

Okay, so just to make sure we're on the same page. In PEP8 style, there should be a blank line between a class's docstring and the first nested function/class (the text you quoted has "one-line" along with "multi-line"). There should not be a blank line if there isn't a docstring. This hold similarly for functions.

[gyscos]

PEP8 says nothing regarding nested functions, and indeed pydocstyle accepts either zero or one (but not more) blank lines between a function docstring and a nested function.