How to select some rows with specific rownames from a dataframe?

You can also use this:

DF[paste0("stu",c(2,3,5,9)), ]

df <- data.frame(x=rnorm(10), y=rnorm(10))
rownames(df) <-  letters[1:10]
df[c('a','b'),]

Assuming that you have a data frame called students, you can select individual rows or columns using the bracket syntax, like this:

• students[1,2] would select row 1 and column 2, the result here would be a single cell.
• students[1,] would select all of row 1, students[,2] would select all of column 2.

If you'd like to select multiple rows or columns, use a list of values, like this:

• students[c(1,3,4),] would select rows 1, 3 and 4,
• students[c("stu1", "stu2"),] would select rows named stu1 and stu2.

Hope I could help.