Function that returns a tuple

John Machin sjmachin at lexicon.net
Sun Jun 17 12:11:11 CEST 2007


On Jun 17, 7:49 pm, Baltimore <alban.lefeb... at gmail.com> wrote:
> On 17 juin, 11:16, Marcpp <mar... at gmail.com> wrote:
>
>
>
> > On 17 jun, 03:53, Dan Hipschman <d... at linux.ucla.edu> wrote:> On Sat, Jun 16, 2007 at 06:30:26PM -0700, Marcpp wrote:
> > > > Hi, I need to returns a tuple from a function (reads a database)
> > > > Any idea?.
>
> > > Like this?
>
> > > def foo():
> > >     return 1, 2, 3, 4
>
> > Hi, I need to return a tupla like this function:
>
> >     def BDllids(a):
> >         a = ()
> >         conn = sqlite.connect('tasques.db')
> >         cursor =  conn.cursor()
> >         cursor.execute('SELECT * FROM tasques')
> >         for row in cursor:
> >             a.append (row[0])
> >         return a()
>
> > I'm doing the correct, method?
>
> Why is 'a' used as argument of the function ?
> You don't need to put it in argument.
>
>      def BDllids():
>          a = ()
>          conn = sqlite.connect('tasques.db')
>          cursor =  conn.cursor()
>          cursor.execute('SELECT * FROM tasques')
>          for row in cursor:
>              a.append (row[0])
>          return a
>
> But that's the correct method !

Say what?

| >>> a = ()
| >>> a.append('x')
| Traceback (most recent call last):
|   File "<stdin>", line 1, in <module>
| AttributeError: 'tuple' object has no attribute 'append'
| >>>

Instead of
    a = ()
the OP should do
    a = []
and at the end,
    return tuple(a)
Of course if the caller is not being so anal as to check that the
returned gizmoid is actually a tuple, then
    return a
would suffice.

Cheers,
John




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