I have a df which looks like the below, There are 2 quantity columns and I want to move the quantities in the "QTY 2" column to the "QTY" column

Note: there are no instances where there are values in the same row for both columns (So for each row, QTY is either populated or else QTY 2 is populated. Not Both)

**DF**

| Index | Product | QTY | QTY 2 |
| --- | --- | --- | --- |
| 0 | Shoes | 5 |  |
| 1 | Jumpers |  | 10 |
| 2 | T Shirts |  | 15 |
| 3 | Shorts | 13 |  |

**Desired Output**

| Index | Product | QTY |
| --- | --- | --- |
| 0 | Shoes | 5 |
| 1 | Jumpers | 10 |
| 2 | T Shirts | 15 |
| 3 | Shorts | 13 |

Thanks