The aim of this activity is to implement an algorithm that returns the union of elements in a collection. Although working with sets is quick and easy in Python, sometimes we might want to find the union between two lists. Create a function called unite_lists, which uses a loop to go through both lists and return common elements. Do not use the built-in set function.

The function in Python is as follows:

def unite_lists(A, B):

   union = []

   for elem in A:

       if elem in B:

           union.append(elem)

   return union

Explanation:

This defines the function

def unite_lists(A, B):

This initializes an empty list for the union list

   union = []

This iterates through list A

   for elem in A:

This checks if the item in list A is in list B

       if elem in B:

If it is present, the item is appended to the union list

           union.append(elem)

This returns the union of the two lists

   return union