I have a dataframe. I would like to apply a function to selected rows. The final idea could be choose the rows according to some parallelization schemes.

Let's say that a I have a dataframe called "dfr". I have also define a function as:

```
def test(xx):

    print(xx)

    return

```

I would like to apply test to each row of my dataframe, I could for example use:

```
dfr.apply(test, axis=1)

```

however, how can I do it for all the rows between the 5th row and 15th row?

I have tried "lambda" but it seems not working.

Thanks for any kind of help