On Mon, Nov 04, 2013 at 11:34:01AM +0100, Ulrich Goebel wrote:
> Hallo,
>
> from a SQLite database I get a value by SELECT s from... which normaly
> is a string, but can be the NULL value, wich means it is not defined. To
> put the value into a form (made by QT) I need a string representation.
>
> str(s) gives either the string itself (which is good) or "None" (which
> is not so good) in the case of NULL. Instead of "None" I would prefer an
> empty string "". How to get that?
if s is None:
value = ''
else:
value = str(s)
But since s is already a string (except for the None case), there's no
need to call str() again.
If you plan of doing this a lot, turn it into a function:
def convert(s):
if s is None:
s = ''
return s
then use it like this:
s = convert(s)
> Possibly there is a build in function smart(s1, s2, s3,...) which
> returns the first s which is a useable string, or even "" if there isn't
> any string in the arguments?
No, but it's trivial to make one yourself:
def smart(*args):
for arg in args:
if arg is not None:
return arg
return ''
--
Steven
_______________________________________________
Tutor maillist - Tutor@python.org
To unsubscribe or change subscription options:
https://mail.python.org/mailman/listinfo/tutor
