Fix my python code, please.

Question

I'm writing a code where i input a set of data A and a corresponding set of data B that are related.
a[0] is connected to b[0]
I want to know which elements in B have their corresponding A element repeated an odd number of times (3,5,7,etc).
The output i want is (7, 8, 9), but instead it gives me (7, 7, 7) and i don't know why!
CODE:
a = [1, 1, 1]
b = [7, 8, 9]
for x in a:
z = a.count(x)
if z%2 and z>1:
print(b[a.index(x)])

Answer 1

The problem is that a.index(x) always returns the index of the first occurrence of x. Here's the corrected code:

a = [1, 1, 1]
b = [7, 8, 9]

for i in range(len(a)):
if a.count(a[i]) % 2 and a.count(a[i]) > 1:
print(b[i])

Answer 2

Thank you brother