Problem
Let's say we have the following dataframe.
```markdown
| | name | items |
|---:|:-------|:-------------------|
| 0 | A | ['item1', 'item2'] |
| 1 | A | ['item3', 'item4'] |
| 2 | B | ['item5'] |
| 3 | B | ['item6'] |
| 4 | C | ['item7', 'item8'] |
```
How do we merge the lists by the column `name`? What we want is a dataframe that looks like the following.
```markdown
| | name | items |
|---:|:-------|:-------------------------------------|
| 0 | A | ['item1', 'item2', 'item3', 'item4'] |
| 1 | B | ['item5', 'item6'] |
| 2 | C | ['item7', 'item8'] |
```