Method check_for_comp

mypy/checkexpr.py:5971–6004

Check the for_comp part of comprehensions. That is the part from 'for': ... for x in y if z Note: This adds the type information derived from the condlists to the current binder.

(self, e: GeneratorExpr | DictionaryComprehension)

            )[0]

    def check_for_comp(self, e: GeneratorExpr | DictionaryComprehension) -> None:
        """Check the for_comp part of comprehensions. That is the part from 'for':
        ... for x in y if z

        Note: This adds the type information derived from the condlists to the current binder.
        """
        for index, sequence, conditions, is_async in zip(
            e.indices, e.sequences, e.condlists, e.is_async
        ):
            if is_async:
                _, sequence_type = self.chk.analyze_async_iterable_item_type(sequence)
            else:
                _, sequence_type = self.chk.analyze_iterable_item_type(sequence)
                if (
                    isinstance(get_proper_type(sequence_type), UninhabitedType)
                    and isinstance(index, NameExpr)
                    and index.name == "_"
                ):
                    # To preserve backward compatibility, avoid inferring Never for "_"
                    sequence_type = AnyType(TypeOfAny.special_form)

            self.chk.analyze_index_variables(index, sequence_type, True, e)
            for condition in conditions:
                self.accept(condition)

                # values are only part of the comprehension when all conditions are true
                true_map, false_map = self.chk.find_isinstance_check(condition)
                self.chk.push_type_map(true_map)

                if codes.REDUNDANT_EXPR in self.chk.options.enabled_error_codes:
                    if mypy.checker.is_unreachable_map(true_map):
                        self.msg.redundant_condition_in_comprehension(False, condition)
                    elif mypy.checker.is_unreachable_map(false_map):
                        self.msg.redundant_condition_in_comprehension(True, condition)

    def visit_conditional_expr(self, e: ConditionalExpr, allow_none_return: bool = False) -> Type:
        self.accept(e.cond)