What is the use of the yield operator and why is it used in generators?

The yield operator in Python is used to create generators — functions that return an iterator. Unlike a regular function, which returns a value and terminates, a generator with yield pauses execution, returns a value, and can be resumed later.

This allows efficient handling of large data volumes without loading everything into memory at once. For example, you can generate elements sequentially as needed.

Example:

def count_up_to(n):
    count = 1
    while count <= n:
        yield count
        count += 1

for number in count_up_to(5):
    print(number)

Here, yield returns the current value of count, and the function's execution is paused until the next call of the iterator.