> Thanks I will try all of that, but what does really means mutating in > python? It's the first time I hear this word in programming :))
An object is called mutable if you can alter it - immutable otherwise. In java and python e.g. strings are immutable. In python, tuples are immutable: >>> a = (1,2) >>> a[0] = 3 TypeError: object doesn't support item assignment but lists are mutable: >>> a = [1,2] >>> a[0] = 3 >>> a [3,2] But objects in tuples can be mutable: >>> a = (1, [2,3]) >>> a[1].append(4) >>> a (1,[2,3,4]) Numbers are also immutable. 1 is 1 always. The most important thing to know about python and variables is that variables are only names pointing/referring to values. You might be able to modify the values if they are mutable, but assigning a value to a variable means that you simply rebind its name to a new value - not that you alter it. Consider this: >>> a = 1 >>> b = a >>> a = 2 >>> print a, b 2 1 -- Regards, Diez B. Roggisch -- http://mail.python.org/mailman/listinfo/python-list
