Your code updated to show the difference between a variable, a class variable, and an instance variable. c = [1, 2, 3, 4, 5] class TEST(): c = [5, 2, 3, 4, 5] ## class variable (TEST.c) def __init__(self): self.c = [1, 2, 3, 4, 5] ## instance variable (a.c)
def add(self, c): self.c[0] = 15 ## instance variable TEST.c[0] = -1 ## class variable c[0] = 100 ## variable/list return c a = TEST() c = a.add(c) print( c, a.c, TEST.c ) -- http://mail.python.org/mailman/listinfo/python-list