For review: PEP 308 - If-then-else expression
Andrew Koenig
ark at research.att.com
Fri Feb 7 18:28:11 EST 2003
Steven> On 2/7/03 3:22 PM, "Gerrit Holl" <gerrit at nl.linux.org> wrote:
>> IMHO, since else is obliged, 'x if a' is not allowed but 'x if a else None'
>> is, which is not intuitive.
Steven> I would agree here that "else" definitely should not be
Steven> obligatory. The "else None" should be implied if the else is
Steven> missing.
But then you have to figure out the meaning of
a if b if c else d
Does it mean
(a if b) if c else d
which would be equivalent to
(a if b else None) if c else d
or does it mean
a if (b if c) else d
which would be equivalent to
a if (b if c else none) else d
This ambiguity goes away if every "if" must have a corresponding "else".
--
Andrew Koenig, ark at research.att.com, http://www.research.att.com/info/ark
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