John Henry wrote:
> Carl Banks wrote:
> <snip>
>> The function can be extended to allow arbitrary arguments. Here's a
>> non-minmal recursive version.
>>
>> def cartesian_product(*args):
>> if len(args) > 1:
>> for item in args[0]:
>> for rest in cartesian_product(*args[1:]):
>> yield (item,) + rest
>> elif len(args) == 1:
>> for item in args[0]:
>> yield (item,)
>> else:
>> yield ()
>>
>>
>
> Very nice.
>
another implementation of cartesian_product using 'reduce' to add
mystery ;-)
def star(outer, inner):
for rest in outer:
for item in inner:
yield rest + (item,)
def cartesian_product(*args):
return reduce(star, args, ((),))
>>> list(cartesian_product("01","01","01"))
[('0', '0', '0'), ('0', '0', '1'), ('0', '1', '0'), ('0', '1', '1'),
('1', '0', '0'), ('1', '0', '1'), ('1', '1', '0'), ('1', '1', '1')]
>>>
Michael
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