Pulling numbers from ASCII filename not working

[mrmakent at cox.net]

First: http://www.catb.org/~esr/faqs/smart-questions.html

You say your program 'crashes' when it gets to 'int(LatString)'.  I'm
guessing (and it's entirely a guess, since you don't tell us) that you
are getting an exception like 'ValueError: invalid literal for int():
whatever'.  I'm guessing again that 'LatString' doesn't contain what
you think it does at this point.  Have you tried inserting a print
statement to show you just what 'LatString' contains?