Some objects (like test mocks) auto-generate new objects on
attribute access, which can lead to an infinite loop in
inspect.unwrap().
Ensuring references are retained to otherwise temporary objects
and capping the size of the memo dict turns this case into a
conventional exception instead.
At the time when an abstract base class' __init_subclass__ runs,
ABCMeta.__new__ has not yet finished running, so in the presence of
__init_subclass__, inspect.isabstract() can no longer depend only on
TPFLAGS_IS_ABSTRACT.
This is still useful for single source Python 2/3 code
migrating away from inspect.getargspec(), but that wasn't
clear with the documented deprecation in place.
inspect.signature now reports the implicit ``.0`` parameters generated by
the compiler for comprehension and generator expression scopes as if they
were positional-only parameters called ``implicit0``.
Patch by Jelle Zijlstra.
The fix for Issue #21217 introduced a regression that caused
`inspect.getsource` to return incorrect results on nested
functions. The root cause of the regression was due to
switching the implementation to analyze the underlying
bytecode instead of the source code.
This commit switches things back to analyzing the source code
in a more complete way. The original bug and the regression
are both fixed by the new source code analysis.
The fix for Issue #21217 introduced a regression that caused
`inspect.getsource` to return incorrect results on nested
functions. The root cause of the regression was due to
switching the implementation to analyze the underlying
bytecode instead of the source code.
This commit switches things back to analyzing the source code
in a more complete way. The original bug and the regression
are both fixed by the new source code analysis.
collections.abc.Awaitable and collections.abc.Coroutine no longer
use __instancecheck__ hook to detect generator-based coroutines.
inspect.isawaitable() can be used to detect generator-based coroutines
and to distinguish them from regular generator objects.
isawaitable() was added before collections.abc.Awaitable; now,
with Awaitable, it is no longer needed (we don't have ishashable()
or isiterable() methods in the inspect module either).
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")
Thomas Kluyver
Jon Dufresne
Dong-hee Na
Nate
Xiang Zhang
Berker Peksag
Nick Coghlan
Yury Selivanov
Guido van Rossum
Martin Panter
Yury Selivanov
Serhiy Storchaka
Meador Inge