black and isort incompatibility within stub files

[gaborbernat]

from tokenize import TokenInfo
from typing import Iterator, List

def replacetokens(tokens: List[TokenInfo], fullname: str) -> Iterator[TokenInfo]: ...
def apply_job_security(code: str) -> str: ...

In this case, black wants to put one line, while isort enforces two.

[gaborbernat]

Workaround for now:

from tokenize import TokenInfo
from typing import Iterator, List

# needed to bypass https://github.com/python/black/issues/837

def replacetokens(tokens: List[TokenInfo], fullname: str) -> Iterator[TokenInfo]: ...
def apply_job_security(code: str) -> str: ...

[JelleZijlstra]

This is probably fixable with a special case in EmptyLineTracker._maybe_empty_lines that adds two newlines between imports and def lines even in stub files, but honestly I'd rather implement import sorting in Black itself.

[timothycrosley]

This is fully configurable in isort, however, isn't isort correct here according to pep8?

In fact, isn't black being self inconsistent, for example black produces this:

from tokenize import TokenInfo
from typing import Iterator, List


def function():
    pass

Adding the extra line if I remove it.
On what basis is black deciding to only use one line above?

[JelleZijlstra]

This is specifically in stub files (.pyi), which use a different, more compact coding style.

[timothycrosley]

@JelleZijlstra this makes sense, is this the standard for pyi files (the lack of the new line), is there an equivalent to pep8 for these files?

[JelleZijlstra]

The closest equivalent is the typeshed coding style: https://github.com/python/typeshed/blob/master/CONTRIBUTING.md#stub-file-coding-style.

[timothycrosley]

@JelleZijlstra thank you! With the additional information, I don't think this is an issue within Black. I'll have a resolution in isort shortly.

~Timothy

[JelleZijlstra]

Thank you!

[timothycrosley]

With version 4.3.19 isort has implemented black's behaviour for stub files

[gaborbernat]

I'll close this then as it stands.