closing files properly opened with urllib2.urlopen()

Question

I have following code in a python script

  try:
    # send the query request
    sf = urllib2.urlopen(search_query)
    search_soup = BeautifulSoup.BeautifulStoneSoup(sf.read())
    sf.close()
  except Exception, err:
    print("Couldn't get programme information.")
    print(str(err))
    return

I'm concerned because if I encounter an error on sf.read(), then sf.clsoe() is not called. I tried putting sf.close() in a finally block, but if there's an exception on urlopen() then there's no file to close and I encounter an exception in the finally block!

So then I tried

  try:
    with urllib2.urlopen(search_query) as sf:
      search_soup = BeautifulSoup.BeautifulStoneSoup(sf.read())
  except Exception, err:
    print("Couldn't get programme information.")
    print(str(err))
    return

but this raised a invalid syntax error on the with... line. How can I best handle this, I feel stupid!

As commenters have pointed out, I am using Pys60 which is python 2.5.4

Answer 1

Given that you are trying to use 'with', you should be on Python 2.5, and then this applies too: http://docs.python.org/tutorial/errors.html#defining-clean-up-actions

Answer 2

Looks like the problem runs deeper than I thought - this forum thread indicates urllib2 doesn't implement with until after python 2.6, and possibly not until 3.1

Answer 3

Why not just try closing sf, and passing if it doesn't exist?

import urllib2
try:
    search_query = 'http://blah'
    sf = urllib2.urlopen(search_query)
    search_soup = BeautifulSoup.BeautifulStoneSoup(sf.read())
except urllib2.URLError, err:
    print(err.reason)
finally:
    try:
        sf.close()
    except NameError: 
        pass

Answer 4

finally:
    if sf: sf.close()