pylint/extensions/overlapping_exceptions.py
def visit_tryexcept(self, node):
        """check for empty except"""
        for handler in node.handlers:
            if handler.type is None:
                continue
            if isinstance(handler.type, astroid.BoolOp):
                continue
            try:
                excs = list(_annotated_unpack_infer(handler.type))
            except astroid.InferenceError:
                continue

            handled_in_clause = []
            for part, exc in excs:
                if exc is astroid.Uninferable:
                    continue
                if isinstance(exc, astroid.Instance) and utils.inherit_from_std_ex(exc):
                    # pylint: disable=protected-access
                    exc = exc._proxied

                if not isinstance(exc, astroid.ClassDef):
                    continue

                exc_ancestors = [
                    anc for anc in exc.ancestors() if isinstance(anc, astroid.ClassDef)
                ]

                for prev_part, prev_exc in handled_in_clause:
                    prev_exc_ancestors = [
                        anc
                        for anc in prev_exc.ancestors()
                        if isinstance(anc, astroid.ClassDef)
                    ]
                    if exc == prev_exc:
                        self.add_message(
                            "overlapping-except",
                            node=handler.type,
                            args="%s and %s are the same"
                            % (prev_part.as_string(), part.as_string()),
                        )
                    elif prev_exc in exc_ancestors or exc in prev_exc_ancestors:
                        ancestor = part if exc in prev_exc_ancestors else prev_part
                        descendant = part if prev_exc in exc_ancestors else prev_part
                        self.add_message(
                            "overlapping-except",
                            node=handler.type,
                            args="%s is an ancestor class of %s"
                            % (ancestor.as_string(), descendant.as_string()),
                        )
                handled_in_clause += [(part, exc)]
def visit_tryexcept(self, node):
        """check for empty except"""
        for handler in node.handlers:
            if handler.type is None:
                continue
            if isinstance(handler.type, astroid.BoolOp):
                continue
            try:
                excs = list(_annotated_unpack_infer(handler.type))
            except astroid.InferenceError:
                continue

            handled_in_clause = []
            for part, exc in excs:
                if exc is astroid.Uninferable:
                    continue
                if isinstance(exc, astroid.Instance) and utils.inherit_from_std_ex(exc):
                    # pylint: disable=protected-access
                    exc = exc._proxied

                if not isinstance(exc, astroid.ClassDef):
                    continue

                exc_ancestors = [
                    anc for anc in exc.ancestors() if isinstance(anc, astroid.ClassDef)
                ]

                for prev_part, prev_exc in handled_in_clause:
                    prev_exc_ancestors = [
                        anc
                        for anc in prev_exc.ancestors()
                        if isinstance(anc, astroid.ClassDef)
                    ]
                    if exc == prev_exc:
                        self.add_message(
                            "overlapping-except",
                            node=handler.type,
                            args="%s and %s are the same"
                            % (prev_part.as_string(), part.as_string()),
                        )
                    elif prev_exc in exc_ancestors or exc in prev_exc_ancestors:
                        ancestor = part if exc in prev_exc_ancestors else prev_part
                        descendant = part if prev_exc in exc_ancestors else prev_part
                        self.add_message(
                            "overlapping-except",
                            node=handler.type,
                            args="%s is an ancestor class of %s"
                            % (ancestor.as_string(), descendant.as_string()),
                        )
                handled_in_clause += [(part, exc)]
check for empty except