I have a TYPE column
and a VOLUME column
What I'm looking to do if first check if TYPE column == 'var1'

If so I would like to make a calculation in the VOLUME column.

So far I have something like this:

```
data.loc[data['TYPE'] == 'var1', ['VOLUME']] * 2
data.loc[data['TYPE'] == 'var1', ['VOLUME']] * 4

```

This seems to set the entire column that meets the condition to the last variable. So I end up with just two values.

Out:

```
4
4
4
4
8
8
8

```

Another option:

```
data['VOLUME'] = data.loc[data['TYPE'] == 'var1', ['VOLUME']] * 2

```

This works for the first condition but show NaN for the second condition
Then when I run:

```
data['VOLUME'] = data.loc[data['TYPE'] == 'var2', ['VOLUME']] * 4

```

The whole column show as NaN.