what exceptions may file() and read() throw?

[Daniel Schüle]

Hello,

currently I am using this instance method

        def getFilecontent(self, filename):
                try:
                        return file(filename).read()
                except IOError, err_msg:
                        print err_msg
                        sys.exit(1)
                except:
                        print "unknown exception in PackageParser"
                        sys.exit(1)

I tried to open a file for which I don't have the permissions to read 
(etc/shadow)
and I tried to open a file which doesn't exist
in both cases I got IOError exception, so my question is
does it make sence to have

                except:
                        print "unknown exception in PackageParser"
                        sys.exit(1)

or is it a dead code?
are there some good reference sources to see what file() and read()
may throw, IMHO it's OS dependent.

Regards, Daniel