Bug report
Bug description:
inspect.markcoroutinefunction() is applied directly to the passed function, except for methods (which is correct behavior). However, inspect.iscoroutinefunction() checks the passed function only after unwrapping (a function that is not wrapped in either functools.partial or functools.partialmethod (currently, _has_coroutine_mark() does not handle these objects; why?)), and thus cannot detect the marker that is not at the end of the unwrapping chain, which results in false negative in cases where a functools.partial/functools.partialmethod object is marked.
>>> from functools import partial
>>> from inspect import iscoroutinefunction, markcoroutinefunction
>>> async def wedonotlikesnakecase():
... return "the_funniest_joke_in_the_world"
>>> def manufacturer_of_jokes(somefunc):
... global manufacturer_of_jokes
... del manufacturer_of_jokes
... return somefunc()
>>> joke = partial(manufacturer_of_jokes, wedonotlikesnakecase)
>>> joke = markcoroutinefunction(joke)
>>> iscoroutinefunction(joke)
False
I discovered this problem while theoretically considering backporting inspect.iscoroutinefunction() to older versions of Python. The problem has not yet been caused by any use case, so it is okay if the issue is closed due to lack of demand. But just in case, I am attaching part of how iscoroutinefunction() is implemented in my code.
def iscoroutinefunction(obj):
marker_name, marker_value = _get_coroutinefunction_marker()
while True: # unwrap & check
if ismethod(obj):
obj = obj.__func__
continue
if marker_value is not MISSING:
if getattr(obj, marker_name, MISSING) is marker_value:
return True
if isinstance(obj, partial):
obj = obj.func
continue
impl = getattr(obj, _partialmethod_attribute_name, MISSING)
if isinstance(impl, partialmethod):
obj = impl.func
continue
# unlike its namesake in the `inspect` module, it does not unwrap
return _has_code_flag(obj, CO_COROUTINE)
CPython versions tested on:
3.12, 3.13, 3.14
Operating systems tested on:
Linux
Linked PRs
Bug report
Bug description:
inspect.markcoroutinefunction() is applied directly to the passed function, except for methods (which is correct behavior). However, inspect.iscoroutinefunction() checks the passed function only after unwrapping (a function that is not wrapped in either functools.partial or functools.partialmethod (currently, _has_coroutine_mark() does not handle these objects; why?)), and thus cannot detect the marker that is not at the end of the unwrapping chain, which results in false negative in cases where a functools.partial/functools.partialmethod object is marked.
I discovered this problem while theoretically considering backporting inspect.iscoroutinefunction() to older versions of Python. The problem has not yet been caused by any use case, so it is okay if the issue is closed due to lack of demand. But just in case, I am attaching part of how iscoroutinefunction() is implemented in my code.
CPython versions tested on:
3.12, 3.13, 3.14
Operating systems tested on:
Linux
Linked PRs