PlexosDB Troubleshooting: Missing 'System' Object Causes Error for bulk Property Addition"

[Bobby-Heyer]

Hi All

Background:

• I am following the Tutorial to bulk insert properties to generator objects, but I am just having a bit of trouble with the API

Issue

• I keep getting error "plexosdb.exceptions.NotFoundError: Object = System not found on the database."
• I've done the properties validation check (as per tutorial) and it seems to work and returns a list of all my generator properties.
• but then when I actually run 'add_properties_from_records' it fails.

Help Requested

Any help on understanding what I am doing wrong would be greatly appreciated.

• I've included snapshot of my code, the error traceback and the results of the valid_props print output.
• I am running Plexos 10.
• print(ClassEnum.System) returns System

CODE:

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

# Initialize database
db = PlexosDB.from_xml("plexosdb.xml")

# Check if properties are valid
valid_props = db.list_valid_properties(
    CollectionEnum.Generators,
    parent_class_enum=ClassEnum.System,
    child_class_enum=ClassEnum.Generator
)
print(f"Valid generator properties: {valid_props}")

# Prepare property records
property_records = [
    {"name": "Generator1", "Offer Quantity": 100.0, Band": 1, "Date From": '01/07/2025', "Date To": '30/06/2026'},
    {"name": "Generator2", "Offer Quantity": 100.0, Band": 1, "Date From": '01/07/2025', "Date To": '30/06/2026'},
    {"name": "Generator3", "Offer Quantity": 200.0, Band": 1, "Date From": '01/07/2025', "Date To": '30/06/2026'},
]

db.add_properties_from_records(
    property_records,
    object_class=ClassEnum.Generator,
    parent_class=ClassEnum.System,
    collection=CollectionEnum.Generators,
    scenario="Base Case"
)

Traceback Error:

Traceback (most recent call last):
  File "c:\Users\user\PycharmProjects\plexosdb_test\test_api.py", line 22, in <module>
    db.add_properties_from_records(
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
        property_records,
        ^^^^^^^^^^^^^^^^^
    ...<3 lines>...
        scenario="Base Case"
        ^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "C:\Users\user\PycharmProjects\Main\.venv\Lib\site-packages\plexosdb\db.py", line 764, in add_properties_from_records
    scenario_id = self.add_scenario(scenario)
  File "C:\Users\user\PycharmProjects\Main\.venv\Lib\site-packages\plexosdb\db.py", line 945, in add_scenario
    object_id = self.add_object(
        ClassEnum.Scenario, name=name, category=category, collection_enum=CollectionEnum.Scenarios
    )
  File "C:\Users\user\PycharmProjects\Main\.venv\Lib\site-packages\plexosdb\db.py", line 571, in add_object
    _ = self.add_membership(ClassEnum.System, class_enum, "System", name, collection_enum)
  File "C:\Users\user\PycharmProjects\Main\.venv\Lib\site-packages\plexosdb\db.py", line 372, in add_membership
    parent_object_id = self.get_object_id(parent_class_enum, parent_object_name)
  File "C:\Users\user\PycharmProjects\Main\.venv\Lib\site-packages\plexosdb\db.py", line 2635, in get_object_id
    raise NotFoundError(msg)
plexosdb.exceptions.NotFoundError: Object = System not found on the database.

Valid Generator Properties (As per Print):

Valid generator properties: ['Must Report', 'Dispatchable', 'Formulate Non-convex', 'Head Effects Method', 'Min Down Time Mode', 'Forced Outage Rate Denominator', 'Repair Time Distribution', 'Fixed Load Method', 'Price Setting', 'Offer Quantity Format', 'Offers Must Clear in Order', 'Unit Commitment Optimality', 'Unit Commitment Aggregation', 'Include in Rounded Relaxation Merit Order', 'Start Profile Range', 'Expansion Optimality', 'Production Decomposition Method', 'Include in Uplift', 'Include in Capacity Payments', 'End Effects Method', 'Decomposition Method', 'Enforce Bounds', 'Is Strategic', 'Transition Type', 'Simultaneous Pump and Generation', 'Model Capital Cost Recovery', 'Scale Participation Factors', 'Simultaneous Increment and Decrement', 'Formulate Risk', 'Project Start Date', 'Commission Date', 'Random Number Seed', 'Max Heat Rate Tranches', 'Unit Commitment Period', 'Rounding Up Threshold', 'Integerization Horizon', 'Internal Volume Scalar', 'Controllable Inflow', 'Decomposition Bound Penalty', 'Units', 'Min Stable Level', 'Min Stable Factor', 'Load Point', 'Generation Credit Start Year', 'Start Cost', 'Start Cost Time', 'Run Up Rate', 'Shutdown Cost', 'Run Down Rate', 'Rolling Planning Bonus', 'Rating Factor', 'Min Up Time', 'Min Up Time Penalty', 'Min Down Time', 'Min Down Time Penalty', 'Max Up Time', 'Max Up Time Penalty', 'Max Down Time', 'Generating Units', 'Must-Run Units', 'Min Load', 'Max Load', 'Max Load Penalty',
'Commit', 'Fuel Mix Penalty', 'Ramp Up Point', 'Max Ramp Up', 'Ramp Down Point', 'Max Ramp Down', 'Rough Running Point', 'Rough Running Range', 'Regulation Point', 'Regulation Range', 'Inertia Constant', 'Aux Fixed', 'Aux Base', 'Aux Incr', 'Marginal Loss Factor', 'Pump Efficiency', 'Pump Load', 'Pump Load Factor', 'Pump Load Penalty', 'Pump Units', 'Min Pump Load', 'Must Pump Units', 'Max Units Pumping', 'Min Pump Time', 'Min Pump Down Time', 'Max Pump Up Time', 'Generation Transition Time', 'Pump Transition Time', 'Sync Cond Units', 'Must-run Sync Cond Units', 'Sync Cond Load', 'Initial Generation', 'Initial Units Generating', 'Initial Hours Up', 'Initial Hours Down', 'Initial Pumping', 'Initial Units Pumping', 'Initial Hours Pumping', 'Last Start State', 'Max Heat Penalty', 'Opening Heat', 'Max Release', 'Max Energy', 'Max Energy Hour', 'Max Energy Day', 'Max Energy Week', 'Max Energy Month', 'Max Energy Year', 'Min Energy', 'Min Energy Hour', 'Min Energy Day', 'Min Energy Week', 'Min Energy Month', 'Min Energy Year', 'Max Capacity Factor', 'Max Capacity Factor Hour', 'Max Capacity Factor Day', 'Max Capacity Factor Week', 'Max Capacity Factor Month', 'Max Capacity Factor Year', 'Min Capacity Factor', 'Min Capacity Factor Hour', 'Min Capacity Factor Day', 'Min Capacity Factor Week', 'Min Capacity Factor Month', 'Min Capacity Factor Year', 'Max Starts', 'Max Starts Hour', 'Max Starts Day', 'Max Starts Week', 'Max Starts Month', 'Max Starts Year',
'Energy Scalar', 'Max Generation Curtailed', 'Max Generation Curtailed Hour', 'Max Generation Curtailed Day', 'Max Generation Curtailed Week', 'Max Generation Curtailed Month', 'Max Generation Curtailed Year', 'Max Generation Curtailment Factor', 'Max Generation Curtailment Factor Hour', 'Max Generation Curtailment Factor Day', 'Max Generation Curtailment Factor Week', 'Max Generation Curtailment Factor Month', 'Max Generation Curtailment Factor Year', 'Max Heat Withdrawal', 'Max Heat Withdrawal Hour',
'Max Heat Withdrawal Day', 'Max Heat Withdrawal Week', 'Max Heat Withdrawal Month', 'Max Heat Withdrawal Year', 'Max Heat Injection', 'Max Heat Injection Hour', 'Max Heat Injection Day', 'Max Heat Injection Week', 'Max Heat Injection Month', 'Max Heat Injection Year', 'Min Heat Withdrawal', 'Min Heat Withdrawal Hour', 'Min Heat Withdrawal Day', 'Min Heat Withdrawal Week', 'Min Heat Withdrawal Month', 'Min Heat Withdrawal Year', 'Min Heat Injection', 'Min Heat Injection Hour', 'Min Heat Injection Day', 'Min Heat Injection Week', 'Min Heat Injection Month', 'Min Heat Injection Year', 'Tie Break Group', 'Risk Level', 'Forced Outage Rate', 'Forced Outage', 'Units Out', 'Maintenance Rate', 'Maintenance Frequency', 'Min Time Between Maintenance', 'Min Total Maintenance Percent', 'Max Total Maintenance Percent', 'Maintenance', 'Outage Factor', 'Initial Operating Hours', 'Mean Time to Repair', 'Min Time To Repair', 'Max Time To Repair', 'Lead Time', 'Technical Life', 'WACC', 'Levelized Capital Carrying Rate', 'Economic Life', 'Max Units Built', 'Max Units Retired', 'Min Units Built', 'Min Units Retired', 'Max Units Built in Year', 'Max Units Retired in Year', 'Min Units Built in Year', 'Min Units Retired in Year', 'Build Set Size', 'Hint Units Built', 'Unit Commitment Non-anticipativity Time', 'Pump Unit Commitment Non-anticipativity Time', 'Generation Non-anticipativity Time', 'Pump Load Non-anticipativity Time', 'Hydro Efficiency Optimality',
'Fixed Load Global', 'Min Load Global', 'Load Subtracter Global', 'Balance Period', 'LCCR Apply Discounting', 'Min Up Time by Cooling State', 'Declining Depreciation Balance', 'Recycle Penalty', 'Decomposition Penalty a', 'Decomposition Penalty b', 'Decomposition Penalty c', 'Decomposition Penalty x', 'Max Capacity', 'Min Stable Level Penalty', 'Fuel Price', 'Heat Rate', 'Heat Rate Base', 'Heat Rate Incr', 'Heat Rate Incr2', 'Heat Rate Incr3', 'VO&M Charge', 'Pump VO&M Charge', 'Generating VO&M Charge', 'FO&M Charge', 'UoS Charge', 'Running Cost', 'Generation Credit', 'Start Profile', 'Start Profile Penalty', 'Start Penalty', 'Shutdown Profile', 'Shutdown Penalty', 'Rating', 'Max Down Time Penalty', 'Fixed Load', 'Fixed Load Penalty', 'Min Load Penalty', 'Ramp Up Charge', 'Max Ramp Up Penalty', 'Ramp Down Charge', 'Max Ramp Down Penalty', 'Natural Inflow', 'Efficiency Base', 'Efficiency Incr', 'Efficiency Degradation', 'Fixed Pump Load', 'Fixed Pump Load Penalty', 'Pump UoS Charge', 'Reserves VO&M Charge', 'Sync Cond VO&M Charge', 'Reserve Share', 'Reference Generation', 'Load Subtracter', 'Price Following', 'Load Following Profile', 'Load Following Factor', 'Boiler Efficiency', 'Heat Load', 'Power to Heat Ratio', 'CHP Electric Heat Rate Incr', 'CHP Heat Surrogate Rate Incr', 'Boiler Heat Rate Incr', 'Max Boiler Heat',
'Max Heat', 'Min Heat', 'Heat Withdrawal Charge', 'Heat Injection Charge', 'Fixed Charge', 'Heat Loss', 'Water Offtake', 'Water Consumption', 'Max Energy Penalty', 'Min Energy Penalty', 'Max Starts Penalty', 'Offer Base', 'Offer No Load Cost', 'Offer Quantity', 'Offer Price', 'Offer Quantity Scalar', 'Offer Price Incr', 'Offer Price Scalar', 'Mark-up', 'Bid-Cost Mark-up', 'Mark-up Point', 'Pump Bid Base', 'Pump Bid Quantity', 'Pump Bid Price', 'Pump Bid Quantity Scalar', 'Pump Bid Price Incr', 'Pump Bid Price Scalar', 'Strategic Rating', 'Strategic Reference Price', 'Strategic Load Rating', 'Economic Maximum', 'Economic Minimum', 'Acceptable Risk', 'Initial Age', 'Capacity Degradation', 'Capacity Degradation', 'Equity Charge', 'Debt Charge', 'Firm Capacity', 'Firm Capacity Unit Count', 'Outage Rating', 'Outage Pump Load', 'Repair Time Shape', 'Repair Time Scale', 'Build Cost', 'Retirement Cost', 'One-time Cost', 'Investment Tax Credit', 'Capacity Price', 'Recovery Price Adder', 'Recovered Capital Cost', 'Unit Commitment Non-anticipativity', 'Pump Unit Commitment Non-anticipativity', 'Generation Non-anticipativity', 'Pump Load Non-anticipativity', 'Build Non-anticipativity', 'Retire Non-anticipativity', 'Pump Timeframe', 'Effective Forced Outage Rate', 'Rating Penalty', 'x', 'y', 'z']

[pesap]

Thanks for using @Bobby-Heyer! Let me have a look at it and will reach out to you.

[mcllerena]

Hi @Bobby-Heyer, the problem here was that this test xml initially does not have a System object, so we need to add it first to link it to the Generator. There's a small bug on the add_object function for adding the "System" though, I'll address this in a PR.
Thanks for noting this.

[davidAlexander08]

I tried setting the scenario to None, since I didn't need a Base Scenario, and I used an XML file that I created in PLEXOS. It did load successfully and exported, but the resulting XML does not include the “Date From” and “Date To” properties, and I still couldn’t get these dates to work.

Also, there was a " missing before Band -> "Band"

code:

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

db = PlexosDB.from_xml("PLEXOS_BASE.xml")

valid_props = db.list_valid_properties(
CollectionEnum.Generators,
parent_class_enum=ClassEnum.System,
child_class_enum=ClassEnum.Generator
)
print(f"Valid generator properties: {valid_props}")

db.add_object(ClassEnum.Generator, "USINA1")
property_records = [
{"name": "USINA1", "Offer Quantity": 100.0, "Band": 1, "Date From": '01/07/2025', "Date To": '30/06/2026'},
{"name": "USINA1", "Offer Quantity": 100.0, "Band": 1, "Date From": '01/08/2025', "Date To": '30/06/2026'},
{"name": "USINA1", "Offer Quantity": 200.0, "Band": 1, "Date From": '01/09/2025', "Date To": '30/06/2026'},
]

db.add_properties_from_records(
property_records,
object_class=ClassEnum.Generator,
parent_class=ClassEnum.System,
collection=CollectionEnum.Generators,
scenario=None
)
db.to_xml("output_model.xml")
output_model.xml
PLEXOS_BASE.xml

[mcllerena]

Hi @davidAlexander08!
I managed to test this code and check it with PLEXOS, indeed these date records are not being added properly. I'll check this in depth and reach back with a solution.

[pesap]

@mcllerena , can you follow up on this?

[mcllerena]

The two issues presented are now addressed and validated on this branch: #78
And the correct way to add the bands and dates, according to the documentation would be:

property_records = [
    {
        "name": "USINA1",
        "properties": {
            "Offer Quantity": {
                "value": 100.0,
                "band": 1,
                "date_from": datetime(2025, 7, 1),
                "date_to": datetime(2026, 6, 30),
            },
            "Max Capacity": {
                "value": 150.0,
                "band": 2,
                "date_from": datetime(2025, 8, 1),
                "date_to": datetime(2026, 12, 31),
            },
        }
    },
    {
        "name": "USINA2",
        "properties": {
            "Offer Quantity": {
                "value": 100.0,
                "band": 1,
                "date_from": datetime(2025, 7, 1),
                "date_to": datetime(2026, 6, 30),
            },
            "Max Capacity": {
                "value": 150.0,
                "band": 2,
                "date_from": datetime(2025, 8, 1),
                "date_to": datetime(2026, 12, 31),
            },
        }
    },
    {
        "name": "USINA3",
        "properties": {
            "Offer Quantity": {
                "value": 100.0,
                "band": 1,
                "date_from": datetime(2025, 7, 1),
                "date_to": datetime(2026, 6, 30),
            },
            "Max Capacity": {
                "value": 150.0,
                "band": 2,
                "date_from": datetime(2025, 8, 1),
                "date_to": datetime(2026, 12, 31),
            },
        }
    },
]

Hope this helps, please let me know if there's any other issue or observation!
Note:
Added an edit on this, since if we want to add more properties with specific bands and dates, then we need to specify them in nested formats as shown above.

[pesap]

Hey @Bobby-Heyer and @davidAlexander08 ,

We updated the way we perform the bulk operation. Have a look at it and let us know if it still works for you! I will be closing this discussion.