On 9 July 2012 00:50, Fred G <bayespoker...@gmail.com> wrote: > I thought it made sense to read the two columns in File1 in as a dictionary > (where the key is actually the name, so that we can search on it later), and
yes... > the column of interest in File2 as a list. Finding the common values then > is just: > > for item in file2_list: > for line in file1_dict: > if item == line: > print item No. Once you have a dictionary from which you can look up id's from names, you want to simply read through the lines in file 2, and for each line, you want to pick up the name from that line and look up the corresponding id using the dict. Then, having looked up the number, you want to then write out a line to a new version of File2 that will replace File2 once done. That's more or less it. Exactly how you handle the old/new File2 issue is up to you. Either write a new file and rename the files once done (safer since you can keep the old file as a backup), or read the entire file into memory and then process and write the whole thing back out to the same file (less safe -- what happens if something goes wrong while you're writing out the data to the file?) Walter _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor