Practice / joins
Waveform's merch team logs sales by product_id, but the report needs human-readable product names.
You have two DataFrames:
sales
products
Your task: for each sale that has a matching product, return the product name and the qty. Sales with no matching product should be dropped.
Assign your answer DataFrame to result. Row order doesn't matter.
salesinput DataFrame| column | type |
|---|---|
| sale_id | long |
| product_id | long |
| qty | long |
| sale_id | product_id | qty |
|---|---|---|
| 1 | 10 | 2 |
| 2 | 11 | 1 |
| 3 | 99 | 5 |
productsinput DataFrame| column | type |
|---|---|
| product_id | long |
| name | string |
| product_id | name |
|---|---|
| 10 | Notebook |
| 11 | Pen |
nameqty· 2 rowssales.join(products, on="product_id", how="inner") keeps only sales whose
product exists, then select("name", "qty").
This problem builds on Joins (~8 min). Pop it open in a new tab if you want a quick recap.