On Tue, 29 Dec 2009 00:49:50 -0500, John Posner wrote:
> On Sun, 27 Dec 2009 09:44:17 -0500, joy99 <subhakolkata1...@gmail.com>
> wrote:
>
>> Dear Group,
>>
>> I am encountering a small question.
>>
>> Suppose, I write the following code,
>>
>> input_string=raw_input("PRINT A STRING:")
>> string_to_word=input_string.split()
>> len_word_list=len(string_to_word)
>> if len_word_list>9:
>> rest_words=string_to_word[9:]
>> len_rest_word=len(rest_words)
>> if len_rest_word>9:
>> remaining_words=rest_words[9:]
>>
>>
> Here's an issue that has not, I think, been addressed in this thread.
> The OP's problem is:
>
> 1. Start with an indefinitely long string.
>
> 2. Convert the string to a list, splitting on whitespace.
>
> 3. Repeatedly return subslices of the list, until the list is exhausted.
>
> This thread has presented one-chunk-at-a-time (e.g. generator/itertools)
> approaches to Step #3, but what about Step #2? I've looked in the Python
> documentation, and I've done some Googling, but I haven't found a
> generator version of the string function split(). Am I missing
> something?
"Indefinitely long" doesn't mean you can't use split.
But if you want a lazy splitter, here's a version which should do what
you want:
def lazy_split(text):
accumulator = []
for c in text:
if c in string.whitespace:
if accumulator:
yield ''.join(accumulator)
accumulator = []
else:
accumulator.append(c)
if accumulator:
yield ''.join(accumulator)
Other alternatives are to use a regex to find runs of whitespace
characters, then yield everything else; or to use the itertools.groupby
function.
--
Steven
--
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