Checking the inequality of several variables in python without knowing their value

Question

I have four string variables: a,b,c,d. I can't know their values (they are assigned randomly), and I don't care. I only need to make sure that every single on of them is different from others and there are not two variables with the same value. I tried

if a != b != c != d:
    return true

but it doesn't work. What should I do?

Answer 1

Do this?

assert len({a, b, c, d}) == 4 # set of 4 distinct elements should be 4

if len({a, b, c, d}) == 4:
    return True

The reason your conditions don’t work

>>> 1 != 2 != 1
True

From the above example, 1 != 2 and 2 != 1, hence passing the condition. It doesn’t check your first and third variable's equality.