Practice / joins
The Daily Grind wants a human-readable order log — who ordered what, for drinks tied to a known customer.
You have two DataFrames:
orders
customers
Your task: for every order that has a matching customer, return the customer's name, the item, and the amount. Orders with no matching customer are dropped.
Assign your answer DataFrame to result. Row order doesn't matter.
ordersinput DataFrame| column | type |
|---|---|
| order_id | long |
| customer_id | long |
| item | string |
| amount | double |
| order_id | customer_id | item | amount |
|---|---|---|---|
| 1 | 100 | Latte | 5.5 |
| 2 | 101 | Mocha | 6 |
| 3 | 999 | Espresso | 3 |
| 4 | 100 | Cold Brew | 6.25 |
customersinput DataFrame| column | type |
|---|---|
| customer_id | long |
| name | string |
| customer_id | name |
|---|---|
| 100 | Priya |
| 101 | Sam |
| 102 | Wei |
nameitemamount· 3 rowsorders.join(customers, on="customer_id", how="inner") keeps only orders with a
known customer, then select("name", "item", "amount").
This problem builds on Joins (~8 min). Pop it open in a new tab if you want a quick recap.