pygeek
June 13, 2024, 5:22am
1
inspect.iscoroutine tests whether an object is of type.CoroutineType
coroutine.iscoroutine tests both type.CoroutineType and collections.abc.Coroutine, as well as, cache the object types for faster lookup on subsequent calls to the function.
What is the reasoning between having these distinct implementations?? Should there be parity between them?
I have a similar inquiry in regards to the inspect.iscoroutinefunction and coroutine.iscoroutinefunction.
pygeek
June 13, 2024, 3:12pm
3
zware
June 13, 2024, 3:57pm
4
You mentioned coroutine.iscoroutine which implies a coroutine module (or object?) with an iscoroutine function (or method?). I believe Éric was asking what that coroutine is, which I’m also confused about coroutine module, and coroutine objects do not have an iscoroutine method, so we’re not sure what you’re comparing to inspect.iscoroutine
pygeek
June 13, 2024, 7:08pm
5
Module, yes asyncio.coroutines.iscoroutine. Apologies for the confusion.
“inspect functions should really be tailored for checking for native types”
committed 04:19PM - 22 Jun 15 UTC
Summary of changes:
1. Coroutines now have a distinct, separate from generators…
type at the C level: PyGen_Type, and a new typedef PyCoroObject.
PyCoroObject shares the initial segment of struct layout with
PyGenObject, making it possible to reuse existing generators
machinery. The new type is exposed as 'types.CoroutineType'.
As a consequence of having a new type, CO_GENERATOR flag is
no longer applied to coroutines.
2. Having a separate type for coroutines made it possible to add
an __await__ method to the type. Although it is not used by the
interpreter (see details on that below), it makes coroutines
naturally (without using __instancecheck__) conform to
collections.abc.Coroutine and collections.abc.Awaitable ABCs.
[The __instancecheck__ is still used for generator-based
coroutines, as we don't want to add __await__ for generators.]
3. Add new opcode: GET_YIELD_FROM_ITER. The opcode is needed to
allow passing native coroutines to the YIELD_FROM opcode.
Before this change, 'yield from o' expression was compiled to:
(o)
GET_ITER
LOAD_CONST
YIELD_FROM
Now, we use GET_YIELD_FROM_ITER instead of GET_ITER.
The reason for adding a new opcode is that GET_ITER is used
in some contexts (such as 'for .. in' loops) where passing
a coroutine object is invalid.
4. Add two new introspection functions to the inspec module:
getcoroutinestate(c) and getcoroutinelocals(c).
5. inspect.iscoroutine(o) is updated to test if 'o' is a native
coroutine object. Before this commit it used abc.Coroutine,
and it was requested to update inspect.isgenerator(o) to use
abc.Generator; it was decided, however, that inspect functions
should really be tailored for checking for native types.
6. sys.set_coroutine_wrapper(w) API is updated to work with only
native coroutines. Since types.coroutine decorator supports
any type of callables now, it would be confusing that it does
not work for all types of coroutines.
7. Exceptions logic in generators C implementation was updated
to raise clearer messages for coroutines:
Before: TypeError("generator raised StopIteration")
After: TypeError("coroutine raised StopIteration")
1 Like
. There is no standard library 
. I was so puzzled by his response.