Bug report

If a bound method is used as the condition for BaseExceptionGroup.split the following exception is raised:

TypeError: expected a function, exception type or tuple of exception types

Consider the following example:

class HandleError: def __enter__(self): pass def __exit__(self, exc_type, exc_inst, exc_tb): if exc_type is None: return False if isinstance(exc_inst, ExceptionGroup): match, rest = exc_inst.split(self._log_and_ignore_error) if match is None: return False elif rest is None: return True raise rest else: return self._log_and_ignore_error(exc_inst) def _log_and_ignore_error(self, e: BaseException) -> bool: ... return True with HandleError(): raise ExceptionGroup('foo', [ValueError('bar')])

If we replace the bound method with a lambda (lambda e: self._log_and_ignore_error(e)) then no exception is raised.

I think it would be useful to accept any callable here. I guess the code update would be simple too, just replace PyFunction_Check with PyCallable_Check in

 if (PyFunction_Check(value)) { *type = EXCEPTION_GROUP_MATCH_BY_PREDICATE; return 0; }

Update the exception message to allow callables, and change the assert in

 case EXCEPTION_GROUP_MATCH_BY_PREDICATE: { assert(PyFunction_Check(matcher_value)); PyObject *exc_matches = PyObject_CallOneArg(matcher_value, exc);

to call PyCallable_Check again.

Your environment

• CPython versions tested on: 3.11.2

The c code snippets are from origin/main.

Linked PRs

• gh-105730: support more callables in ExceptionGroup.split() and subgroup() #106035