To chek if list A is completely included in list B – all elements of list A are present in list B, we can use the “superset” and “subset” methods of the standard Python “set” class.
Converting lists to sets also allows us not to worry about checking for duplicates if they exist in the compared lists.
The “subset” method acts on a smaller set and checks if it is in a larger set.
A = ['a', 'x', 'z']
A1 = ['a', 'x', 'z', 99]
B = list('abcdefghijklmnopqrstuvwxyz') # ['a', 'b', ..., 'z']