Error in exception handling 

def fun(a , b):
    try:
        c = ((a+b) / (a-b))
    except logicError:
        print ("a/b result in 0")
    else:
        print (c)
 
fun(4.0, 6.0)
fun(6.0, 6.0)

in <module>fun(6.0, 6.0)
except logicError:
NameError: name 'logicError' is not defined

I am getting a logicError in that above exception handling program. I need help in this program.