How to sort an array based on the length of each element?

Question

I have an array like this:

arr = []
arr[0] = \"ab\"
arr[1] = \"abcdefgh\"
arr[2] = \"abcd\"

After sorting, the output array should be:

Answer 1

#created a sorting function to sort by length of elements of list
def sort_len(a):
    num = len(a)
    d = {}
    i = 0
    while i