Documenting Python coroutines with Sphinx autodoc - python-asyncio

Question

I'm starting to document my first asyncio-based project with Sphinx. I noticed some projects have this "coroutine" prefix before some methods and I'd like to do the same in my project's documentation, but I can't figure out how.
For example, aiohttp's HTTP client reference shows this:
class aiohttp.ClientSession(...):
coroutine request(...)
That project seems to use a coroutinemethod directive to achieve this, but I document all my functions and classes inline using docstrings and this directive only works if you write the docs in a reStructuredText document.
Does anybody know how to achieve this result with autodoc?
Edit: I will also accept answers that explain how to make a Sphinx extension to do this if Sphinx doesn't support it. Bonus points if someone can point my to some kind of way that automatically detects whether the method is a coroutine or not using inspect.iscoroutinefunction().
Edit: I'm looking at the "pyspecific" Sphinx extension in the CPython project for inspiration. However, I need to change autodoc's behavior, not add new directives. After a bit of research, it looks like autodoc has an autodoc-process-signature event which can be used to customize the function signature, but it doesn't seem to have the object used by the "pyspecific" extension.

Answer 1

This functionality is not already built-in to Sphinx. However, pull request #1826 adds support for generators, coroutine functions, coroutine methods with built-in detection of coroutines in autodoc's autofunction and automethod directives.
Here is a patch that I applied locally to enable this in Sphinx 1.4 (requires disabling sphinx-build's -W "turn warnings into errors" option):
# Recipe stolen from open PR (https://github.com/sphinx-doc/sphinx/pull/1826).
from inspect import iscoroutinefunction
from sphinx import addnodes
from sphinx.domains.python import (
PyClassmember,
PyModulelevel,
)
from sphinx.ext.autodoc import FunctionDocumenter as _FunctionDocumenter
from sphinx.ext.autodoc import MethodDocumenter as _MethodDocumenter
class PyCoroutineMixin(object):
"""Helper for coroutine-related Sphinx custom directives."""
def handle_signature(self, sig, signode):
ret = super(PyCoroutineMixin, self).handle_signature(sig, signode)
signode.insert(0, addnodes.desc_annotation('coroutine ', 'coroutine '))
return ret
class PyCoroutineFunction(PyCoroutineMixin, PyModulelevel):
"""Sphinx directive for coroutine functions."""
def run(self):
self.name = 'py:function'
return PyModulelevel.run(self)
class PyCoroutineMethod(PyCoroutineMixin, PyClassmember):
"""Sphinx directive for coroutine methods."""
def run(self):
self.name = 'py:method'
return PyClassmember.run(self)
class FunctionDocumenter(_FunctionDocumenter):
"""Automatically detect coroutine functions."""
def import_object(self):
ret = _FunctionDocumenter.import_object(self)
if not ret:
return ret
obj = self.parent.__dict__.get(self.object_name)
if iscoroutinefunction(obj):
self.directivetype = 'coroutine'
self.member_order = _FunctionDocumenter.member_order + 2
return ret
class MethodDocumenter(_MethodDocumenter):
"""Automatically detect coroutine methods."""
def import_object(self):
ret = _MethodDocumenter.import_object(self)
if not ret:
return ret
obj = self.parent.__dict__.get(self.object_name)
if iscoroutinefunction(obj):
self.directivetype = 'coroutinemethod'
self.member_order = _MethodDocumenter.member_order + 2
return ret
def setup(app):
"""Sphinx extension entry point."""
# Add new directives.
app.add_directive_to_domain('py', 'coroutine', PyCoroutineFunction)
app.add_directive_to_domain('py', 'coroutinemethod', PyCoroutineMethod)
# Customize annotations for anything that looks like a coroutine.
app.add_autodocumenter(FunctionDocumenter)
app.add_autodocumenter(MethodDocumenter)
# Return extension meta data.
return {
'version': '1.0',
'parallel_read_safe': True,
}