I have a wide data frame.

Year <- c(2020, 2021)
Percent_a <- c(10,10)
Percent_b <- c(12,10)
Percent_c <- c(2,4)
Percent_d <- c(4,5)

df <- data.frame(Year, Percent_a, Percent_b, Percent_c, Percent_d)

I would like to have my data is the following format:

Year  Item  Percent
2020  a     10
2020  b     12
2020  c     2
2020  d      4
2021  a     10
2021  b     10
2021  c     4
2021  d     5

I tried this:

df %>%
  pivot_longer(
    cols = -Year,
    names_to = c(".value", "Percent"),
    names_pattern = "(.)_(.*)",
    values_to = "Percentage"
  ) ->df_longer

It almost worked but I got something like this – what is “t”?

Year  Percent  t
2020  a        10
2020  b        12
2020  c        2
2020  d        4
2021  a        10
2021  b        10
2021  c        4
2021  d        5