Question

I’m writing a function that squares each element in the list.

def square(num):
    for i in range(len(num)):
        square[i] = square[i] ** 2

def action():
    nums = [2, 3, 4]
    print square(nums)


action() 

It returns an error:

    square[i] = square[i] ** 2
TypeError: 'function' object has no attribute `__getitem__`.

Ideas?

Answer 1

Within your square function you are referring to the function as if it’s a list:

def square(num):
    for i in range(len(num)):
        square[i] = square[i] ** 2

Because square is not a list, Python tries to ask it for item i with the __getitem__ method, but that doesn’t exist either.

Perhaps you meant to use num instead?

def square(num):
    for i in range(len(num)):
        num[i] = num[i] ** 2