Lukasz,
If you have a file GDB from which you are importing attributed shapes, you will want to use CGA rules (Python not needed here) to read those attributes and use the attribute data to help create the generated model. To do this, first create an attribute in your CGA rule, like this:
attr MatchingNameGoesHere = 42 # (default value)
The CGA attribute name must match exactly (case sensitive) the attribute in the GDB. Next, apply this rule to the shapes in question. Upon applying this rule, CE will see the matching names and then connect the CGA attribute in the Inspector to the Object Attribute coming from the GDB. If it does not occur automatically, or if the rule was previously applied to this shape, you can manually make this connection by clicking the Attribute Connection Editor next to the attribute value in the inspector. This will only work of the names match. If you need for the names to not match, then you can get the same effect using the Layer Attributes option inside the Attribute Connection Editor.
Does this work for you?
Chris