batch tiff to jpeg conversion script

[Larry Bates]

rtilley at vt.edu wrote:
> Hope it's not inappropriate to post this here.
> 
> Could someone critique my code? I have no Python programmers in my
> office to show this to. The script works OK, but should I do it
> differently? I especially don't like how I check to see if jpegs exist.
> 
> The style may not be acceptable to some, but I'm concerned with
> substance, not style. Is there a 'more appropriate' way to do this?
> 
> Thanks to all who take the time to give advice!
> 
> -----------------------------------------------------------------
> import os
> import os.path
> #From PIL
> import Image
> 
> def tiff_to_jpeg(path):
> 
>     for root, dirs, files in os.walk(path):
>         for f in files:
>             if os.path.splitext(os.path.join(root,f))[1].lower() ==
> ".tif":
> 
>                 # If a jpeg is already present. Don't do anything.
>                 if
> os.path.isfile(os.path.splitext(os.path.join(root,f))[0] + ".jpg"):
>                     print "A jpeg file already exists for %s" %f
> 
>                 # If a jpeg is *NOT* present, create one from the tiff.
>                 else:
>                     outfile = os.path.splitext(os.path.join(root,f))[0]
> + ".jpg"
>                     try:
>                         im = Image.open(os.path.join(root,f))
>                         print "Generating jpeg for %s" %f
>                         im.thumbnail(im.size)
>                         im.save(outfile, "JPEG", quality=100)
>                     except Exception, e:
>                         print e
> 
> # Run Program
> path = '.'
> tiff_to_jpeg(path)
> 
The methodology seems just fine.  You may (or may not) find
the following code easier to read (not tested):

    for f in [file for file in files if file.lower().endswith('.tif')]:
        # If a jpeg is already present. Don't do anything.
	filename, extension=f.split('.')
        jpgfile="%s.jpg" % filename
        jpgpath=os.path.join(root, jpgfile)
        # If a jpeg is *NOT* present, create one from the tiff.
        if not os.path.isfile(jpgpath):
            try:
                im = Image.open(os.path.join(root,f))
                print "Generating jpeg for %s" % f
                im.thumbnail(im.size)
                im.save(jpgpath, "JPEG", quality=100)
             except Exception, e:
                print e

             continue

        print "A jpeg file already exists for %s" % f


This code:

1) only processess .tif files
2) simplifies things by eliminating the splitext methods and
   slicing operations.
3) eliminates else branch

-Larry Bates