Thanks, everyone, for taking the time to reply to my question!  I liked the
simplicity of Kyle Bannerjee's command line suggestion, but stumbled over
how to get the "cat" command to work on my Windows machine and couldn't
figure out how to properly implement GnuWin32, so I went with a variation
of Hannah's solution, using this formula in Excel:

=IF(COUNTIF($C:$C, $A2)=0, "No", "Match!")

On Fri, Nov 10, 2017 at 4:16 PM, Kyle Breneman <[log in to unmask]>
wrote:

> I have 2 Excel files, each with a column of barcodes.  I am supposed to
> determine which, if any, of the barcodes in the first file are also present
> in the second file.  Is writing a short Python program the best way to do
> this, or is there a more efficient way?  (There are about 300 items in the
> first file and about 1,000 items in the second file.)
>
> Regards,
> Kyle
>