You can simly use a for loop with append to list. list1 = ['lion', 'dog', 'cat', 'tiger', 'cat', 'cat', 'zebra'] list2 = ['monkey', 'tiger', 'cow', 'mouse'] my_list = [] for animal in list1: #iterating over list1 if animal not in list2 and animal not in my_list: my_list.append(animal) #add item to tRead more