Ternary operator alternative in Ptyhon
stargaming at gmail.com
Wed Jun 18 08:27:33 CEST 2008
On Tue, 17 Jun 2008 23:18:51 -0700, kretik wrote:
> I'm sure this is a popular one, but after Googling for a while I
> couldn't figure out how to pull this off.
> Let's say I have this initializer on a class:
> def __init__(self, **params):
Why not ``__init__(self, mykey=None)`` in the first place?
> I'd like to short-circuit the assignment of class field values passed in
> this dictionary to something like this:
> self.SomeField = \
> params.has_key("mykey") ? params["mykey"] : None)
> Obviously I know this is not actual Python syntax, but what would be the
> equivalent? I'm trying to avoid this, basically:
> if params.has_key("mykey"):
> self.SomeField = params["mykey"]
> self.SomeField = None
> This is not a big deal of course, but I guess my main goal is to try and
> figure out of I'm not missing something more esoteric in the language
> that lets me do this.
> Thanks in advance.
You're lucky -- Python 2.5 just grew a ternary if-construct. You'd use it
self.SomeField = params["mykey"] if "mykey" in params else None
# or, generically: TRUE if CONDITION else FALSE
Notice the use of the `in` operator, which is recommended over
Robert "Stargaming" Lehmann
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