Catching an exception while using a Python 'with' statement

Question

Hello,

To my shame, I can't figure out how to handle exception for python 'with' statement. If I have a code:

with open("a.txt") as f:
    print f.readlines()

I really want to handle 'file not found exception' in order to do somehing. But I can't write

with open("a.txt") as f:
    print f.readlines()
except:
    print 'oops'

and can't write

with open("a.txt") as f:
    print f.readlines()
else:
    print 'oops'

enclosing 'with' in a try/except statement doesn't work else: exception is not raised. What can I do in order to process failure inside 'with' statement in a Pythonic way?

Answer 1

from __future__ import with_statement

try:
    with open( "a.txt" ) as f :
        print f.readlines()
except EnvironmentError: # parent of IOError, OSError *and* WindowsError where available
    print 'oops'

Answer 2

I just tried, enclosing the with in a try/except works fine.

try:
  with open("dummy.txt", "r") as f:
    print(f.readlines())
except:
  print("oops")

Answer 3

with open("x.txt") as f:
    data = f.read()
    do something with data

Answer 4

This code works fine in python 2.5.1:

from __future__ import with_statement

try:
    with open('non-existent.txt') as f:
        print f.readlines()
except:
    print "Exception"