In pursuit of creating something equivalent to the struct of Matlab in Python, I want to create a class that is designed so that when an instance of it is given a new attribute that the class as a whole doesn't yet have, the class is automatically declared to have an attribute of that name (but dynamic value).

For example, if I have defined the class `color` in this manner, but having no attributes to start with, then I could do the following:

```
>> red = color()
>> blue = color()
>> blue.temperature
   AttributeError: type object 'color' has no attribute 'temperature'
>> red.temperature = 'hot'
>> blue.temperature
   blue.temperature = ''
>> blue.temperature = 'cool'

```

Is there a way to hack the process of adding another attribute and add to it a command like `cls.x = ''`, with `x` being a variable for the name of the attribute added to the instance?