If you create an iterator, don’t attempt to pass it between threads. You can share the objects yielded by an iterator, as long as they’re thread-safe, but don’t share the iterator itself across thread boundaries. For instance, to create an iterator that produces the letters from a string one after the other, you could do this:
data = "abcdefg"
d_iter = iter(data)
item = next(d_iter)
item2 = next(d_iter)
# ... etc.
In this example, d_iter is the iterator object. You could share data and item (or item2, etc.) between threads, but you can’t share d_iter itself between threads, as that’s likely to corrupt its internal state.
Python frame objects contain information about the state of a program at a particular point in its execution. Among other things, they’re used by Python’s debugging mechanisms to produce details about the program when an error condition arises.
