For review: PEP 308 - If-then-else expression

Andrew Koenig ark at research.att.com
Sat Feb 8 00:31:21 CET 2003


Skip> On Fri, 7 Feb 2003, Guido van Rossum wrote:

>> The proposed syntax is as follows:
>> <expression1> if <condition> else <expression2>

Skip> +0 from me.  For the times I've needed such a construct

Skip>     <cond> and <expr1> or <expr2>

Skip> has generally been sufficient.

except that this construct has a subtle pitfall:  If <cond> is true
and <expr1> is false, the result is <expr2> instead of <expr1>.
To get around it, you have to write something like

        (<cond> and [expr1] or [expr2])[0]

which is truly obscure.

-- 
Andrew Koenig, ark at research.att.com, http://www.research.att.com/info/ark




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