Hello Object's attributes can be created dynamically, ie
class MyClass: pass obj = MyClass() obj.test = 'foo' but why doesn't it work with built-in classes int, float, list.... ? L = [1, 8, 0] L.test = 'its a list !' (however lists are mutable, int, float ... are not) Traceback (most recent call last): File "<pyshell#29>", line 1, in <module> L.test = 'its a list !' AttributeError: 'list' object has no attribute 'test' but it works on functions: def funct(a,b): ....print(a+b) funct.test = 'this is a function' funct.test 'this is a function' -- https://mail.python.org/mailman/listinfo/python-list