Hi, if u check the id's of a and b lists and also its elements, you will obeserve that the id's of a and b have changed but id's of their elements have not changed. If you make a deep copy of the list a and then make your changes in that list, it shud work. this can be done using the copy module.
hope that helps, vaibhav >>> id(a) -1208622388 >>> id(b) -1208622324 >>> for el in a: ... print id(el) ... -1208622836 -1208622708 -1208622772 -1208622420 >>> for el in b: ... print id(el) ... -1208622836 -1208622708 -1208622772 -1208622420 >>> import copy >>> c = copy.deepcopy(a) >>> id(c) -1208464564 >>> for el in c: ... print id(el) ... -1208465172 -1208464276 -1208464180 -1208463988 -- http://mail.python.org/mailman/listinfo/python-list