如何在 R 中将分层数据（从超过 20/20）从部分宽格式转换为长格式？

Question

I have some census data which is partially in long and partially in wide format that was exported from Beyond 20/20. I am struggling with how to reformat the data, since it is not totally in wide format as is. In the following data set, there is the number of male and female people for each education level and state. For example:

> have
  State Education Male Female
1    CA         1    3      4
2    CA         2    4      6
3    NV         1    7      8
4    NV         2    9     19

However, I want the data to be fully long format. This would mean having the number of individuals that are in each unique state, education, and sex category. For example:

> want
  State Education    Sex Number
1    CA         1   Male      4
2    CA         1 Female      3
3    CA         2   Male      4
4    CA         2 Female      6
5    NV         1   Male      7
6    NV         1 Female      8
7    NV         2   Male      9
8    NV         2 Female     19

Thanks in advance for any thoughts or advice.

Answer 1

We could use pivot_longer from tidyr package:

library(tidyr)
library(dplyr)
df %>% 
  pivot_longer(
    cols=c(Male, Female),
    names_to = "Sex", 
    values_to = "Number"
  )

  State Education Sex    Number
  <chr>     <int> <chr>   <int>
1 CA            1 Male        3
2 CA            1 Female      4
3 CA            2 Male        4
4 CA            2 Female      6
5 NV            1 Male        7
6 NV            1 Female      8
7 NV            2 Male        9
8 NV            2 Female     19