delete_property fails with AssertionError when System object is not named "System"

[Bobby-Heyer]

Hi team,

I am encountering two issues I was hoping to get some help with.

ISSUE 1:
an AssertionError when using db.delete_property() on a model where the root System object is named something other than "System" (e.g., in my case, it is named "NEM").

If I rename the object in the XML from "NEM" to "System", the code works perfectly. This leads me to believe delete_property (and other plexosdb functions) might be defaulting the parent_object_name to "System" internally when parent_class=ClassEnum.System is passed, rather than looking up the actual name of the system object.

Is this correct or is this just user-error and PEBKAC on my part.

To Reproduce:

1. Load an XML where the System object is named "NEM".
2. Attempt to delete a property from a Generator.

CODE:

from plexosdb import PlexosDB
from plexosdb.enums import ClassEnum, CollectionEnum

# 1. Setup
xml_path = r"C:\Users\User\Downloads\example_plexos.xml"
db = PlexosDB.from_xml(xml_path)

# 2. specific target details
target_gen = "BW01"
target_prop = "Max Capacity"

# 3. Identify the System Object Name (Debug step)
# This confirms if your system is named "NEM", "System", or something else
system_objects = db.list_objects_by_class(ClassEnum.System)
current_system_name = system_objects[0] if system_objects else "None Found"
print(f"DEBUG: Current System Object Name in XML is: '{current_system_name}'")

# 4. Attempt Delete
print(f"Attempting to delete '{target_prop}' from Generator '{target_gen}'...")

try:
    db.delete_property(
        ClassEnum.Generator,
        target_gen,
        property_name=target_prop,
        parent_class=ClassEnum.System,
        collection=CollectionEnum.Generators
    )
    print("SUCCESS: Property deleted.")
except AssertionError as e:
    print(f"FAILED: AssertionError encountered. The library likely expected parent 'System' but found '{current_system_name}'.")
    raise e

ASSERTION ERROR:

Traceback (most recent call last):
  File "C:\Users\bobby.heyer\PycharmProjects\plexosdb_test\test_api.py", line 25, in <module>
    db.delete_property(
    ~~~~~~~~~~~~~~~~~~^
        ClassEnum.Generator,
        ^^^^^^^^^^^^^^^^^^^^
    ...<3 lines>...
        collection=CollectionEnum.Generators
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "C:\Users\User\PycharmProjects\Main\.venv\Lib\site-packages\plexosdb\db.py", line 2199, in delete_property
    membership_id = self.get_membership_id(parent_object_name, object_name, collection)
  File "C:\Users\User\PycharmProjects\Main\.venv\Lib\site-packages\plexosdb\db.py", line 2595, in get_membership_id
    assert result
           ^^^^^^
AssertionError

ISSUE 2

Assuming I rename 'System' and successfully delete a property, I am also having issues trying to add new properties in.

I am able to add the property, but for the wrong parent_class. I am trying to add to Collection = Generators and Parent Class = System. but instead it is adding it to the wrong collection / parent class

I suspect the issue to be with 'parent_class=ClassEnum.System,'

CODE:

# 5. Attempt to Add a Record
print('######## ADD PROPERTIES ########')

# Flat format (recommended)
flat_records = [
    {"name": "BW01", "property": "Max Capacity", "value": 150},
]

db.add_properties_from_records(
    flat_records,
    object_class=ClassEnum.Generator,
    parent_class=ClassEnum.System,
    collection=CollectionEnum.Generators,
    scenario='',
)
print("SUCCESS: Property Added.")

[pesap]

Hey @Bobby-Heyer!

Thanks for reporting this issues and sorry for the inconvenience. On the first issue, I did not know that you could have a system object being named different than "system". That is an easy fix that we can do on our end to avoid the assertion errors. I will relax the default System class name and it should fix also your second issue.

[Bobby-Heyer]

Thanks @pesap

On issue 2, i think it's more around the Child object / parent object relationship. It would be great to have another input where we can set the parent_object for bulk add properties.

[pesap]

I have an open PR for it. Can you give it a try? #96

[Hasakev]

Hi there, while testing this issue, we encountered a new error (#97)

[pesap]

Can you check #100