len(mystr) = 4
mystr[1] = b
mystr[1:] = bcd
mystr[1:3] = bc
mystr[:-2] = ab
c = a
c = c

len(mylist) = 4
mylist[1] = x
len(mylist[1:]) = 3
c = w
c = y
b != a
c != a
d != a

a == b  ->  0
a != b  ->  1
a == y  ->  1
a != y  ->  0
a == n  ->  0
a != n  ->  1