[Python-Dev] "funny".split("")
Brian Quinlan
brian@sweetapp.com
2002年3月12日 10:23:20 -0800
Christian wrote:
> I'm just translating the Python Pocked Reference the
> second time, and I stumbled over this:
>> "funny".split("")
>> gives a ValueError: empty separator.
>> Why this?
> I would expect
>> ['f','u','n','n','y']
Why wouldn't you expect this:
['', 'f', 'u', 'n', 'n', 'y', '']
As with:
>>> ' f u n n y '.split(' ')
['', 'f', 'u', 'n', 'n', 'y', '']
> as result, since this is the maximum result of undoing
>> "".join(['f','u','n','n','y'])
>> For what reason is this asymmetry?
There will always be asymmetry because there are many lists that, when
joined by the empty string, return in the same string e.g.
>>> ''.join(['fun', 'ny'])
'funny'
>>> ''.join(['', 'f', 'u', 'n', 'n', 'y', ''])
'funny'
>>> ''.join(['f', 'u', 'n', 'n', 'y'])
'funny'
But the split method can only return one list.
Cheers,
Brian