Nested try...except

Magnus.Moraberg at gmail.com Magnus.Moraberg at gmail.com
Wed Apr 2 15:22:50 CEST 2008


On 2 Apr, 15:15, Magnus.Morab... at gmail.com wrote:
> On 2 Apr, 15:12, cokofree... at gmail.com wrote:
>
>
>
> > On Apr 2, 3:06 pm, Magnus.Morab... at gmail.com wrote:
>
> > > Hi,
>
> > > I found the following code on the net -
>
> > > http://mail-archives.apache.org/mod_mbox/httpd-python-cvs/200509.mbox/%3C20050924104732.5116.qm...@minotaur.apache.org%3E
>
> > > def count(self):
> > > -            db = sqlite.connect(self.filename,
> > > isolation_level=ISOLATION_LEVEL)
> > > -            try:
> > > -                try:
> > > -                    cur = db.cursor()
> > > -                    cur.execute("select count(*) from sessions")
> > > -                    return cur.fetchone()[0]
> > > -                finally:
> > > -                    cur.close()
> > > -            finally:
> > > -                db.close()
>
> > > I don't understand though why the second try is not after the line cur
> > > = db.cursor(). Can anyone explain for me why?
>
> > > /Barry.
>
> > Better question is why is there a try with no except...
>
> > Better yet, WHY is there two TRY statements when there could quite
> > happily be only one...
>
> > Towards what you are asking, I GUESS...because the author hoped to
> > handle the cases where cur failed to get assigned...but then
> > his .close method of it would likely not work anyway...I mean...does
> > this even work...YUCK
>
> I shouldn't have written "Nested try...except" as the title, instead I
> mean "Nested try...finally". Sorry about that...
>
> Anyway, how would you do this? That is, use a finally to close the
> network connection and the cursor?
>
> Thanks for your help,
>
> Barry

Here's what I would do. Is it OK?

    def ExecuteWithNoFetching(self, queryString):

        sqlServerConnection = adodbapi.connect (";".join (connectors))
        try:
            cursor = sqlServerConnection.cursor()
            try:
                cursor.execute(queryString)
                raise Exception("Exception")
                sqlServerConnection.commit()
            finally:
                cursor.close()
        finally:
            sqlServerConnection.close()



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