Did you read open, split, join, map, or make even a cursory effort to search answers already available here?

I ask, because we prefer to teach, rather than do-for, those who bow "and send Praises."

We also take the soft soap more seriously if you trouble yourself to read

• On asking for help
• How do I post a question effectively?
• Markup in the Monastery
• I know what I mean. Why don't you?

Update: upon rereading this screed, I see I've failed to be specific about the reference to "I know what I mean;..." :

Given your OP, we have no idea of the format of the "text" files in particular WRT the "first column" - are you talking about a simple text file, a CSV or Tab Delimited File or something else.