Question

def fun1(a):

    for i in range(len(a)):
        a[i] = a[i] * a[i]
    return a

Answer 1

It takes an array as parameter and returns the same array with each member squared.

EDIT:

Since you modified your question from ‘What does this function do’ to ‘What is some code to execute this function’, here is an example:

def fun1(a):
    for i in range(len(a)):
        a[i] = a[i] * a[i]
    return a

test1 = [1,2,3,4,5]
print 'Original list', test1
test2 = fun1(test1)
print 'Result', test2
print 'Original list', test1

The output will be:

Original list [1, 2, 3, 4, 5]
Result [1, 4, 9, 16, 25]
Original list [1, 4, 9, 16, 25]

Because the function modifies the list in place, test1 is also modified.