Rhodri James wrote:
On Mon, 04 May 2009 15:25:44 +0100, Antoon Pardon
<apar...@forel.vub.ac.be> wrote:
On 2009-04-24, Steven D'Aprano <st...@remove-this-cybersource.com.au>
wrote:
On Fri, 24 Apr 2009 03:00:26 -0700, GC-Martijn wrote:
Hello,
I'm trying to do a if statement with a function inside it. I want to
use
that variable inside that if loop , without defining it.
def Test():
return 'Vla'
I searching something like this:
if (t = Test()) == 'Vla':
print t # Vla
or
if (t = Test()):
print t # Vla
Fortunately, there is no way of doing that with Python. This is one
source of hard-to-debug bugs that Python doesn't have.
I think this is an unfortunate consequence of choosing '=' for the
assignment. They could have chosen an other token to indicate an
assignment one that would have made the difference between an
assignment and a comparison more visually different and thus
bugs by using one while needing the other less hard to track
down.
What token could be used and still be meaningful, though? Algol
used ":=", which has most of the same problems as "=" (more, in my
opinion, since it fools the eye more easily if you're scanning
printed code quickly). Easily constructed arrows like "<=" or
"<-" collide with different comparators. About all that's left
that even vaguely implies assignment is "~", and it's no better.
If you're not limited to ASCII then there's '←' (U+2190, 'LEFTWARDS
ARROW'). It's a little too late now, though.
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