Enforce blank line after module docstring

[lsorber]

Black does not have an opinion on whether there should be a blank line immediately after a module's docstring. This causes inconsistencies across blackened files because whatever the author chooses, stays.

Both examples below satisfy black:

"""Module docstring."""

import typing

"""Module docstring."""
import typing

My preference would be to enforce a blank line.

Related issue: #450

[JelleZijlstra]

Agree that we should add a blank line here.

[felix-hilden]

A moderate +1 for the proposal. To get a feel for multiline docstrings and some more imports:

"""
Multiline docstring.

That explains details about the module.
"""
import stuff
import antigravity

from __future__ import braces

# VS

"""
Multiline docstring.

That explains details about the module.
"""

import stuff
import antigravity

from __future__ import braces

I don't have a strong preference either way. Personally I don't add the empty line because the """ is enough of a separator, but that's not a hill I'm willing to die on 😄 I'd be happy with either 👍