Error python : [ZeroDivisionError: division by zero]

Catch the error and handle it:

try:
    z = x / y
except ZeroDivisionError:
    z = 0

Or check before you do the division:

if y == 0:
    z = 0
else:
    z = x / y

The latter can be reduced to:

z = 0 if y == 0 else (x / y) 

Or if you’re sure y is a number, which implies it`s truthy if nonzero:

z = (x / y) if y else 0
z = y and (x / y)   # alternate version