How do you get the logical NAND of two variables in Python

Since NAND is the negation of and, I would assume

not (a and b ) 

should totally work, with a and b as inputs or do I miss something?.

Interpreting:

Tree 2's x and y both are not the same as Tree 1's x and y

As:

Tree 2's x and y are not both the same as Tree 1's x and y

return (t1.x, t1.y) != (t2.x, t2.y)