Create a sample of order data

create_order_data.py

from datetime import datetime
import pandas as pd

orders = pd.DataFrame(
    data={
        'customer': [1, 2, 3, 2, 3, 1, 1],
        'order_date': [
            datetime(2018, 1, 3),
            datetime(2018, 1, 5),
            datetime(2018, 1, 7),
            datetime(2018, 1, 8),
            datetime(2018, 1, 9),
            datetime(2018, 1, 10),
            datetime(2018, 1, 10)
        ],
        'amount': [25, 42, 116, 21, 83, 4, 67]
    }
)

print(orders)