RFC: Assignment as expression (pre-PEP)

[Bruno Desthuilliers]

TimeHorse at gmail.com a écrit :
> I would like to gauge interest in the following proposal:
> 
> Problem:
> 
> Assignment statements cannot be used as expressions.

This is by design.

> Performing a list of mutually exclusive checks that require data
> processing can cause excessive tabification.  For example, consider
> the following python snipet...
> 
> temp = my_re1.match(exp)
> if temp:
>   # do something with temp
> else:
>   temp = my_re2.match(exp)
>   if temp:
>     # do something with temp
>   else:
>     temp = my_re3.match(exp)
>     if temp:
>       # do something with temp
>     else:
>       temp = my_re4.match(exp)

OMG.

actions = [
   (my_re1, do_something_with_temp1),
   (my_re2, do_something_with_temp2),
   (my_re3, do_something_with_temp3),
   (my_re4, do_something_with_temp4),
]

for my_re, do_something_with in actions:
   temp = my_re.match(exp):
   if temp:
     do_something_with(temp)
     break

Having full-blown anonymous functions or Ruby/Smalltalk-like code blocks 
would be much more interesting IMHO.