“Return” in Function only Returning one Value

Question

Let\'s say I write a for loop that will output all the numbers 1 to x:

x=4
for number in xrange(1,x+1):
    print number,
#Output:
1
2
3
4

Answer 1

What you want is is called a Generator:

def counter(x):
    for number in xrange(1,x+1):
        yield number

You would then use it like this:

c = counter(5)
next(c)  # 1
next(c)  # 2

You could also consume the entire generator by doing:

xs = list(c)  # xs = [1, 2, 3, 4, 5]

See: http://docs.python.org/2/tutorial/classes.html#generators for more information.

The return statement in Python returns form the function and does not save any state. Every time you call the function a new stack frame is created. yield on the other hand is (more or less) Python's equivilent of continutations