如何使用正则表达式对 r 中的数据框列 select ？

Question

I have the following data frame.

D <- data.frame(A123.case.vs.B123.Cntl._FC = 1:4, B123.case.vs.B123.Cntl._FC = 0:3, A123.case.vs.D123.Cntl._FC= 2:5, FC = 1:4, A123.case= 0:3, B123.cntrl = 0:3)

I would like to select the first 3 columns using regular expression.

here is what I am trying but it does not work.

D %>% select(contains("case.vs.[a-z]*[0-9].cntl"))

Do you have any idea where is my problem?

Thanks

Answer 1

The following regular expression does what the question asks for.

library(dplyr)

D %>% select(matches('case\\.vs\\.[[:alpha:]][[:digit:]]+'))
#  A123.case.vs.B123.Cntl._FC B123.case.vs.B123.Cntl._FC A123.case.vs.D123.Cntl._FC
#1                          1                          0                          2
#2                          2                          1                          3
#3                          3                          2                          4
#4                          4                          3                          5