Using String Methods In Jump Tables

Bruno Desthuilliers bruno.42.desthuilliers at websiteburo.invalid
Wed Aug 25 12:35:27 CEST 2010


Tim Daneliuk a écrit :
> On 8/19/2010 7:23 PM, Steven D'Aprano wrote:
>> On Thu, 19 Aug 2010 18:27:11 -0500, Tim Daneliuk wrote:
>>
>>> Problem:
>>>
>>>   Given tuples in the form (key, string), use 'key' to determine what
>>>   string method to apply to the string:
>>>>> table = {'l': str.lower, 'u': str.upper}
>>>>> table['u']('hello world')
>> 'HELLO WORLD'
>>
> 
(snip)
 >
> Yeah ... those old assembler memories never quite fade do they.
> I dunno what you might call this.  A Function Dispatch Table
> perhaps?

I usually refers to this idiom as "dict-based dispatch". And FWIW, it's 
in fact (part of...) polymorphic dispatch implemention in Python's 
object model:

 >>> str.__dict__['lower']
<method 'lower' of 'str' objects>
 >>> d = dict(l="lower", u="upper")
 >>> s = "aHa"
 >>> for k, v in d.items():
...     print "%s : %s" % (k, s.__class__.__dict__[v](s))




More information about the Python-list mailing list