Unnecessary/Redundant __iter__ method with ListMixin class (contrib.gis.geos.mutable_list.py)?

[Joshua Bixby]

The ListMixin class (contrib.gis.geos.mutable_list.py) currently has an __iter__ method and __getitem__ method. Typically iteration is implemented using one or the other, not both. Looking at the two methods, the __iter__method appears to be unnecessary since the Python interpreter will use __getitem__to iterate if __iter__ is not present. Also, stepping through code appears to have __iter__ call __getitem__, which raises the question of why define an __iter__ method when the interpreter can use __getitem__directly.

Currently, __getitem__ can't be used properly for iteration because of the custom IndexError raised in the _checkindex method. Switching from raising a django.contrib.gis.geos.error.GEOSIndexError exception to a exceptions.IndexError will allow for the interpreter to use __getitem__for iteration, which would allow removing the unnecessary or redundant __iter__ method.

[Tim Graham]

Could you propose a patch with a regression test?

[Tim Graham]

It looks like #4740 is the reason the way this code is the way it is, but the template engine lookups now catch IndexError too, so we may be able to remove the custom exception.

[Tim Graham]

​PR

[Tim Graham <timograham@…>]

In 197b187:

Fixed #25225 -- Simplified code to remove GEOSIndexError

The test is a regression for refs #4740 to show that the original
fix of GEOSIndexError is no longer needed.

[Tim Graham <timograham@…>]

In 35800ac:

Refs #25225 -- Removed test for removed ListMixin._IndexError.

Unused since 197b1878105504b5ac7e399e1f52a6093c88baa3.