Split strings into columns in R where each string has a potentially different number of column entries

Question

I\'ve got a data frame that\'s got the following form

pages                         count
[page 1, page 2, page 3]      23
[page 2, page 4]              4
[p         


        

Answer 1

My "splitstackshape" package has a function that addresses this kind of problem. The relevant function in this case is concat.split and works as follows (using "myDat" from Ricardo's answer):

# Get rid of "[" and "]" from your "pages" variable
myDat$pages <- gsub("\\[|\\]", "", myDat$pages)
# Specify the source data.frame, the variable that needs to be split up
#   and whether to drop the original variable or not
library(splitstackshape)
concat.split(myDat, "pages", ",", drop = TRUE)
#   count pages_1 pages_2 pages_3
# 1    23  page 1  page 2  page 3
# 2     4  page 2  page 4        
# 3    12  page 1  page 3  page 4