Re: [Tutor] recursive generator

[Stefan Behnel]

Steven D'Aprano, 07.03.2010 14:27:
On Sun, 7 Mar 2010 11:58:05 pm spir wrote:
     def __iter__(self):
         ''' Iteration on (key,value) pairs. '''
         print '*',
         if self.holdsEntry:
             yield (self.key,self.value)
         for child in self.children:
             print "<",
             child.__iter__()
             print ">",
         raise StopIteration


__iter__ should be an ordinary function, not a generator. Something like
this should work:

# Untested.
     def __iter__(self):
         ''' Iteration on (key,value) pairs. '''
         def inner():
             print '*',  # Side effects bad...
             if self.holdsEntry:
                 yield (self.key,self.value)
             for child in self.children:
                 print "<",
                 child.__iter__()
                 print ">",
             raise StopIteration
         return inner()

That's just an unnecessarily redundant variation on the above. It's 
perfectly ok if __iter__() is a generator method.

Stefan

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