Check if list contains only item x

Question

Say all of w, x, y, and z can be in list A. Is there a shortcut for checking that it contains only x--eg. without negating the other variables?

w, x, y, and z

Answer 1

That, or if you don't want to deal with a loop:

>>> a = [w,x,y,z]
>>> a.count(x) == len(a) and a

(and a is added to check against empty list)