On Sat, Jun 30, 2012 at 11:59 PM, <fiatjaf@yahoo.com.br> wrote:
the idea is to make an variable assignment at the same time that the existence of that variable -- which is being returned by a function -- is made.
suppose we are returning a variable from the method 'get' from the 'request' object and them making some stuff with it, but that stuff we will only do if it exists, if not, we'll just pass, instead of writing:
variable = self.request.get('variable') if variable: print variable
we could write
if self.request.get('variable') as variable: print variable
seems stupid (or not?), but with lots of variables to process, this pre-assignment could be very unpleasant -- especially if, as the in the example case, very little use will be made of the tested variable.
also, the "as" expression already exists and is very pythonic.
This proposal has been considered and rejected many times. It's not general enough - it *only* works for those cases where the value to be retained *and* the interesting condition are the same. Consider the simple case of a value that may be either None (not interesting) or a number (interesting). Since the interesting values include "0", which evaluates as False along with None, this limited form of embedded assignment syntax would not help. Embedded assignment in C isn't that limited., but nobody has yet volunteered to take the radical step of proposing "(X as Y)" as a general embedded assignment syntax. I suggest anyone consider such an idea do a *lot* of research in the python-ideas archives first, though (as the idea has seen plenty of discussion). It is not as obviously flawed as the if-and-while statement only variant, but it would still involve being rather persuasive to make such a significant change to the language. You're also unlikely to get much in the way of core developer feedback until after the 3.3 release in August. Cheers, Nick. -- Nick Coghlan | ncoghlan@gmail.com | Brisbane, Australia