PEP 308: Pep Update

[James J. Besemer]

Andrew Dalke wrote:
> Raymond Hettinger:
> 
>>The leading options on the table are:
>>
>>*     (if <cond>: <expr1> else: >expr2>)
> 
> 
> BTW, I never did see a response to this comment of mine.  With the
> above syntax, this means the following is legal
> 
>   # get the 2-ple of name's value and who owns it
>   a = (
>     #  The value can be cached or in the database
>     if is_cached:
>       self._get_cache[name]
>     else:
>       self.connection.fetch(name),  # database already open when getting
> source
> 
>      # The ownership is stored in the database (if the
>      # name starts with "DB") or from the web service
>      if x.startswith("DB")
>        self.connection.get_owner(name)
>      else:
>        self.webservice.get_owner_by_name(name)
>   )
> 
> That is, code which in the small looks like normal Python if/else
> statement is really an if/else expression once you look in the
> larger scope, which may be indefinitely away.  

As pointed out, the required parentheses make it less of an issue.

Furthermore, (although I know you'll disagree) I'll point out that your 
general complaint here also constitutes an argument for going with the 
operator based alternative,

	a ? b : c

as it couldn't possibly be confused with if/else statements.

> Also note that
> the indentation level does not matter inside of the "a=(...)"
> expression.

This has always been the case within expressions.  I agree the insides of 
multi-line expressions should usually be indented but here you have 
discovered yet another of the thousands of ways Python code is subject to 
"abuse" by naive or sinister coders.

> I don't like that.  I would rather use two temporary names.

I respect your preference and I'm even willing to FIGHT for your right to 
always have that choice.

I just wish you'd be willing to be more flexible about other people's opinion 
about style.

Regards

--jb


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