Perlish dictionary behavior

Chetan Gadgil cgadgil_list at cxoindia.dnsalias.com
Wed Jun 9 04:44:19 CEST 2004


>>> class AllThingsStartAtZero(dict):
...     def __getitem__(self, key):
...          return dict.get(self, key, 0)
...


> -----Original Message-----
> From: 
> python-list-bounces+cgadgil_list=cxoindia.dnsalias.com at python.
> org 
> [mailto:python-list-bounces+cgadgil_list=cxoindia.dnsalias.com
> @python.org] On Behalf Of Fred Allen
> Sent: Wednesday, June 09, 2004 6:24 AM
> To: python-list at python.org
> Subject: Re: Perlish dictionary behavior
> 
> 
> Mr. Brewer:
> 
> I fruitlessly tried your "thing counter", as you can see below. 
> 
> >>> class AllThingsStartAtZero(dict):
> ... 	def getitem (self, key):
> ... 		return dict.get(self, key, 0)
> ... 	
> >>> thingCounts = AllThingsStartAtZero() for thing in
> >>> ('a','b','c','d','a'):
> ... 	thingCounts[thing] += 1
> ... 	
> Traceback (most recent call last):
>   File "<interactive input>", line 2, in ?
> KeyError: 'a'
> >>> thingCounts
> {}
> 
> Reason tells me it should work for me using...
> 
> PythonWin 2.3.4 (#53, May 25 2004, 21:17:02) [MSC v.1200 32 
> bit (Intel)] on win32.
> 
> ...as it did for you. The runtime interpreter, however, says 
> otherwise. Can you see what I've done wrong...I can't?
> 
> With thanks in advance, I am,
> 
> Respectfully yours,
> 
> Fred Allen
> -- 
> http://mail.python.org/mailman/listinfo/python-list
> 





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