我有一个像下面这样的文件..
abc, 12345
def, text and nos
ghi, something else
jkl, words and numbers
abc, 56345
def, text and nos
ghi, something else
jkl, words and numbers
abc, 15475
def, text and nos
ghi, something else
jkl, words and numbers
abc, 123345
def, text and nos
ghi, something else
jkl, words and numbers
我想将其转换（加入）为：
abc, 12345, 56345, 15475, 123345
def, text and nos, text and nos,text and nos,text and nos
ghi, something else, something else, something else, something else
jkl, …