Python iterator when underlying object changes

Question

I would like to know what\'s the general behaviour of an iterator if the underlaying object changes during the iteration.

Using a simple mutable list, it seems obvi

Answer 1

There are some iterators that can yield more data even after a StopIteration has been raised; such iterators are considered broken.

This does not mean the iterator is at fault -- it means that if you use such an iterator without caution you can end up with bugs and broken code.