in reply to Parse csv file line by line
Your results for a script not what others are getting running same script? Your results not changing when you change the script? Then one thing you can do is check to make sure that the script you think is running is actually the script you are running, e.g., put a print statement at the top of the script that you know has to show up the next time you run the script. If you are on Linux, the quick way to ensure you are running the script (let's call it "myscript.pl") in the current working directory is to prefix it with "./" when you call it, i.e., "./myscript.pl".
Another thing to check is that if you are working in a Linux environment with a Windows generated text file, that you use "dos2unix" on the file before manipulating it. This debugging check is related to the "non-printing character" comments already made above.
Your dialog with the other commentors made me think the above may be worth mentioning.