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annoying behavior

Larry Bates lbates at syscononline.com
Tue Sep 28 16:26:26 EDT 2004 
Elbert Lev wrote:
> # here is the problem I ran into:
> 
> class foo:
>     def __init__(self, host):
>         self.f()
>         self.r = True
>     
>     def f(self):
>         if self.r:
>             #<do something>
>             pass
>         else:
>             #<do something else>
>             pass
> 
> f = foo("1234")
> 
> #here is the output:
> 
> #Traceback (most recent call last):
> #  File "G:\MyProjects\Python\Little\inconv.py", line 16, in ?
> #    f = foo("1234")
> #  File "G:\MyProjects\Python\Little\inconv.py", line 5, in __init__
> #    self.f()
> #  File "G:\MyProjects\Python\Little\inconv.py", line 9, in f
> #    if self.r:
> #AttributeError: foo instance has no attribute 'r'
> 
> # I understand why does this happen, but, to tell the truth,
> # this feature is very annoying. 
> # Are there any plans to relax this restriction? 
> # In 3.0 :)?

Just put the lines in the correct order:

  class foo:
      def __init__(self, host):
          self.r = True
          self.f()

      def f(self):
          if self.r:
              #<do something>
              pass
          else:
              #<do something else>
              pass

  f = foo("1234")

You can't ask if self.r is True (which is what you do
in the second line of the f() method) before it actually
exists.

Larry Bates
Syscon, Inc.
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