On Sep 19, 9:59 pm, Peng Yu <pengyu...@gmail.com> wrote: > Hi, > > I know that strings or numbers are immutable when they passed as > arguments to functions. But there are cases that I may want to change > them in a function and propagate the effects outside the function. I > could wrap them in a class, which I feel a little bit tedious. I am > wondering what is the common practice for this problem. > > Regards, > Peng
Python strings and numbers are always immutable, not just when passed as arguments. "propagate the effects outside the function" is a little vague. You can return new data objects (like str.lower() etc.. do) or you can wrap them in a namespace (a dict or class instance) or you can pass a list object that contains the string or int or whatever, and your functions can replace the values in the dict/instance/list. HTH, ~Simon -- http://mail.python.org/mailman/listinfo/python-list
