IndexError: list index out of range

i is the value and not the position, looping through the list [3, 5, 7], i would first equal 3, then 5 and finally on the third iteration 7. Depending where you are in the loop by doing x[i] you are saying x[3], x[5] or x[7]. The error occurs as soon as it hits x[3] as this is out of range, as are the other possibilities. In essence i already contains the value you want.

One thing I’ve noticed is that the indentation character (presumably a tab) must be there for the code to run properly. I took the original code in step 1:

for i in range(0,3):
print n[i]

and stuck it in a function and I received the same error you received. When I positioned myself on the end of the for statement line and hit the delete key until the next line was immediately after the for statement, I hit the “Enter” key [CRLF] to recreate the indentation and the error went away.

This code works without errors, as long as I regenerate the CRLF->tab after the for statment.

n = [3,5,7]
def myFun(n):
    for i in range(0,3):
        print n[i]

Don’t forget to change n to x inside the function

x[i] is the ith element of x.

Your code is, the first time in the loop, trying x[3], which is out of bounds of the array.