how to return diff in a list in python code example

Example 1: how to subtract 2 lists in python

[item for item in x if item not in y]

Example 2: get list of words that are in two lists using set

list1 = ['little','blue','widget']
list2 = ['there','is','a','little','blue','cup','on','the','table']

list3 = set(list1)&set(list2) # we don't need to list3 to actually be a list

list4 = sorted(list3, key = lambda k : list1.index(k))