import pandas as pd

orders = pd.DataFrame(
    {
        "order_id": [1042, 1038, 1040, 1041, 1039],
        "region": ["West", "East", "East", "North", "West"],
        "total_usd": [275.0, 410.0, None, 365.0, 190.0],
    }
)

source_order = orders["order_id"].tolist()