Generator is a function that produces an iterator. Therefore, once you have iterator instance, use next() to fetch the next item from the iterator.
As an example, use next() function to fetch the first item, and later use for in to process remaining items:
# create new instance of iterator by calling a generator function
items = generator_function()
# fetch and print first item
first = next(items)
print('first item:', first)
# process remaining items:
for item in items:
print('next item:', item)