""" For this part of the problem set
you will be generating your own functions
to achieve a specific goal. """

""" Create a function length which counts the number
of elements in a list without using the built-in len. """

""" Create a function sum_iteratable which takes in
a list and returns the sum of all its elements. """

""" Create a function weighted_sum which takes a list and returns the
sum of all the numbers in the list multiplied by their index. e.g. [5, 12, 3] = 5 * 0 + 12 * 1 + 3 * 2. """

""" Create a function remove_duplicates which takes in a list and 
returns a new list with all duplicates removed. """

""" Create a function stringerz which takes in a string and returns
a new string which each character appearing in the string extended by index number of times. 
e.g "hello" -> "heelllllllooooo". """

""" Create a function perform_op which takes in a list and a function 
and returns the sum of applying the function to each element in the list. 
e.g. perform_op([1,2,3], lambda x: x*2) -> 1*2 + 2*2 + 3*2. """