The expansion of c is a tuple of pairs, zip then creates an iterator (iirc zips get exhausted so iterator and not iterable); the unpack then calls dunder iter o

The expansion of c is a tuple of pairs, zip then creates an iterator (iirc zips get exhausted so iterator and not iterable); the unpack then calls dunder iter of the iterator. The iterator returns itself; and the destructing expands the iterator to exactly two items and binds them to a,b