yield and next in python code example

Example: python generator

# A generator-function is defined like a normal function, 
# but whenever it needs to generate a value, 
# it does so with the yield keyword rather than return. 
# If the body of a def contains yield, 
# the function automatically becomes a generator function.
# Python 3 example
def grepper_gen():
  yield "add"
  yield "grepper"
  yield "answer"
grepper = grepper_gen()
next(grepper)
> add
next(grepper)
> grepper
next(grepper)
> answer