staticmethod makes my brain hurt

[Dotan Cohen]

On Thu, Nov 17, 2011 at 04:30, Roy Smith <roy at panix.com> wrote:
> When I run this (python 2.6.1):
>
> class C:
>    @staticmethod
>    def foo():
>        pass
>
>    print "inside", foo, callable(foo)
>
> print "outside", C.foo, callable(C.foo)
>
> I get:
>
> inside <staticmethod object at 0x421df0> False
> outside <function foo at 0x41e6f0> True
>
> I don't understand.  Why is foo not callable inside of the class
> definition?  Where this comes up is that I'm trying to use a callable
> default in mongoengine:
>
> class User(Document):
>    @staticmethod
>    def _get_next_id():
>      [blah, blah, blah]
>      return id
>
>    user_id = IntField(required=True, default=_get_next_id)
>
> The way mongoengine works is if callable(default) is true, it calls
> default() to get the real value to use.  At the point where the
> IntField() call is made, _get_next_id is not callable, and eventually I
> end up with:
>
> ValidationError: <staticmethod object at 0x2a3c1a0> could not be
> converted to int

Try this (untested):

class C:
   @staticmethod
   def foo():
       pass

   print "inside", C.foo, callable(C.foo)



-- 
Dotan Cohen

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