[python] Return outside function error in Python

You can only return from inside a function and not from a loop.

It seems like your return should be outside the while loop, and your complete code should be inside a function.

def func():
    N = int(input("enter a positive integer:"))
    counter = 1
    while (N > 0):
        counter = counter * N
        N -= 1
    return counter  # de-indent this 4 spaces to the left.

print func()

And if those codes are not inside a function, then you don't need a return at all. Just print the value of counter outside the while loop.