split strings on first and last commas

Question

I would like to split strings on the first and last comma. Each string has at least two commas. Below is an example data set and the desired result.

A similar ques

Answer 1

Using str_match() from package stringr, and a little help from one of your links,

> library(stringr)
> data.frame(str_match(my.data$my.string, "(.+?),(.*),(.+?)$")[,-1], 
             some.data = my.data$some.data)
#    X1        X2    X3 some.data
# 1 123  34,56,78    90        10
# 2  87     65,43    21        20
# 3  a4        b6 c8888        30
# 4  11      bbbb ccccc        40
# 5  uu     vv,ww    xx        50
# 6   j k,l,m,n,o     p        60