How to get the union of two lists using list comprehension? [duplicate]

If you have more than 2 list, you should use:

>>> a = ['Orange and Banana', 'Orange Banana']
>>> b = ['Grapes', 'Orange Banana']
>>> c = ['Foobanana', 'Orange and Banana']
>>> list(set().union(a,b,c))
['Orange and Banana', 'Foobanana', 'Orange Banana', 'Grapes']

>>> list(set(a).union(b))
['Orange and Banana', 'Orange Banana', 'Grapes']

Thanks @abarnert