Hello Christophe,

can you please post the drawing file here? Please, export it with Export loaded drawing files with resources (hopefully there will be not too much resources in the .zip file ). I want to investigate the connection between the door and the room.

After some tests I came up to a conclusion, that a PythonPart cannot be a child object of a room (or any other object) at the moment, because it loses the ability to be modified. Meaning: as soon as there is a Parent-Child link added between a PythonPart and another object (room, a smart symbol), then when trying to modify the PythonPart with double click, an error appears (PythonPartProcessor.cpp). This error is definitely not a result of your wrong syntax. It is an Allplan internal error.

What is your goal in this case? Maybe we can solve it on some other way?

You don't have to transfer the information about a parent object into the object, you want to evaluate, by any kind of script. If you want to generate a list of the doors/windows/etc. and include the information of the rooms (or other parent objects) they belong to, you can always call the PARENT(...) function of the Allplan formula interpreter, when evaluating the content of a drawing file. For example,
the following query in a report (in the section <CommandText>):

SELECT
@10@[Name=AllrightBauteilID],
Name=ParentLength|f=PARENT(@220@)]
FROM [Filter=@OBJ@.eq.1760,Type=0]

If you want to keep an information about the parent object in the PythonPart, consider the formula Attributes, that can also refer to parent objects.

The problem you will encounter here is, that your PythonParts cannot be a CHILD object of anything, as long as you wand to keep the modification feature.

As far as I know, there is the possibility of changing the attributes in bimplus and import them back to Allplan. Both, export/import of attributes into an excel sheet as well as exchange with bimplus, are worth considering. I guess, only you can evaluate, what is better to accomplish your goal.