Python: Adding Fields to Objects Dynamically

I am wondering whether it is possible to add fields to objects dynamically. For example, I 开发者_运维问答want to be able to add something like:

user = object()
user.first_name = 'John'
user.last_name = 'Smith'

When I execute that in Python command line interpretor I get:

AttributeError: 'object' object has no attribute 'first_name'

Any idea?

Try this:

class Object:
    pass

obj = Object()
obj.x = 5

You cannot assign to attributes of object instances like this. Derive from object, and use an instance of that class.