Proposed PEP for a Conditional Expression
Gareth McCaughan
Gareth.McCaughan at pobox.com
Tue Sep 11 18:56:06 EDT 2001
Terry Reedy wrote:
[Christian Tanzer:]
> > Conditional expressions provide some nice benefits totally
> > unrelated to lambdas.
> > One example: with a trivial class, one can put expressions into
> > format directives, like
> > "Found %(number)d error%(if number == 1 : '' else : 's')s" % trivial
>
> Python does not evaluate expressions inside strings and I do not
> expect it ever will.
class Trivial:
def __getitem__(self, key):
return eval(key, globals(), locals())
"foo %(1+2+3)s bar" % Trivial() ===> "foo 6 bar"
Giving it access to the caller's local variables
isn't quite so easy.
--
Gareth McCaughan Gareth.McCaughan at pobox.com
.sig under construc
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