Same here - 
```python
for tab_list in tabs.InvalidCourseTabList():
    from_json_result = tab_list.from_json(tab_list.tabs)
    self.assertEquals(len(from_json_result), len(tab_list))
```
This is less brittle and the following lines inside the loop look a lot nicer. It's nicer, cleaner, safer, and much more Pythonic to iterate directly over items.