You could have done flights[['year', 'month', 'day']].head(10) which is not so different from standard R head(flights[c("year", "month", "day")], 10)

You could have done flights[['year', 'month', 'day']].head(10) which is not so different from standard R head(flights[c("year", "month", "day")], 10) but it's true that the following may be nicer flights[1:10, c("year", "month", "day")] (by the way using head(10) is not the same as indexing 1:10 if there are less than 10 rows)