method:wrong structure

Chris Rebert clp2 at rebertia.com
Thu Sep 15 04:39:48 EDT 2011


2011/9/15 守株待兔 <1248283536 at qq.com>:
> there are  three  programs,all of them  left  main  structure,
> code0 is ok,i don't know why code2 and code3 can't run,how to fix them?
> code0
> class   webdata(object):
>     def  __init__(self,arg):
>
>     def  loadequity(self):
>
>     def  loadoption(self):
>
>     #loadstatus={'equity':self.loadequity(),'option':self,loadoption()}
>
>     def  run(self):
>
> if  __name__=="__main__":
>      s=webdata('equity').run()
>      s.loadequity()
>
> code1
> class   webdata(object):
>     def  __init__(self,arg):
>
>     def  loadequity(self):
>
>     def  loadoption(self):
>
>     loadstatus={'equity':self.loadequity(),'option':self,loadoption()}

Class definitions are executable code. So the assignment to loadstatus
happens *while the class webdata is still being defined*. There is
therefore no class instance object or `self` at this point, hence the
error when you try and do self.loadequity(): you're trying to call an
instance method before it's even possible for there to be instances of
the class.

Cheers,
Chris
--
http://rebertia.com



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