Generator issue in Python

I was trying to understand generators in Python and implemented this:

def yfun():
    print("into y fun ... ")
    for x in range(1,6):
        print("tryin to yield : {}".format(x))
        yield x

yieldVar = yfun()

for val in yieldVar:
   print("value generated -> ", val)

The output comes as below:

into y fun ...
tryin to yield : 1
value generated ->  1
tryin to yield : 2
value generated ->  2
tryin to yield : 3
value generated ->  3
tryin to yield : 4
value generated ->  4
tryin to yield : 5
value generated ->  5

Can you please explain why is the function being called again and again ? Isn't the variable supposed to have the values and iteration should be done on generator variable ?