Sorting your data frame

Alright, now that you understand the order$()$ function, let us do something useful with it$.$ You would like to rearrange your data frame such that it starts with the smallest planet and ends with the largest one. A sort on the diameter column.

Instructions

$100$ XP

Call order$()$ on planets$\_$df$diameter $($the diameter column of planets$\_$df$).$ Store the result as positions.

Now reshuffle planets$\_$df with the positions vector as row indexes inside square brackets. Keep all columns. Simply print out the result.