[mod_python] Global Variables

Does using global variables in mod-python handler affect the performance ?
I am using Publisher handler as follows :-
....
x #global variable
y  #global variable
....
def func1(req):
    .....
    .....
    use x and y
    .....
    .....

def func2(req):

    .....
    use x and y
    .....

please do reply
Thanks in advance ,
Regards ,
Ajinkya