Downloading files using urllib in a for loop?

[justsee at gmail.com]

Hi,
 I'm using Python 2.3 on Windows for the first time, and am doing
something wrong in using urllib to retrieve images from urls embedded
in a csv file. If I explicitly specify a url and image name it works
fine(commented example in the code), but if I pass in variables in this
for loop it throws errors:

--- The script:

import csv, urllib
reader = csv.reader(open("source.csv"))
for x,y,z,imagepath in reader
  theurl = imagepath[:55]
  theimage = imagepath[55:-8]
  urllib.urlretrieve(theurl, theimage)
  #urllib.urlretrieve("http://someurl/image.gif", "image.gif") # works!

--- The errors:

This throws the following errors:
  File "getimages.py", line 9, in ?
    urllib.urlretrieve(theurl,theimage)
  File "C:\Python23\lib\urllib.py", line 83, in urlretrieve
    return _urlopener.retrieve(url, filename, reporthook, data)
  File "C:\Python23\lib\urllib.py", line 213, in retrieve
    fp = self.open(url, data)
  File "C:\Python23\lib\urllib.py", line 181, in open
    return getattr(self, name)(url)
  File "C:\Python23\lib\urllib.py", line 410, in open_file
    return self.open_local_file(url)
  File "C:\Python23\lib\urllib.py", line 420, in open_local_file
    raise IOError(e.errno, e.strerror, e.filename)
IOError: [Errno 2] No such file or directory: ''

---

Would really appreciate some pointers on the right way to loop through
and retrieve images, as I've tried various other solutions but am
clearly missing something simple!

Thanks,

justin.