Help with splitting

[Jeremy Bowers]

On Fri, 01 Apr 2005 14:20:51 -0800, RickMuller wrote:

> I'm trying to split a string into pieces on whitespace, but I want to
> save the whitespace characters rather than discarding them.
> 
> For example, I want to split the string '1    2' into ['1','    ','2'].
> I was certain that there was a way to do this using the standard string
> functions, but I just spent some time poring over the documentation
> without finding anything.

importPython 2.3.5 (#1, Mar  3 2005, 17:32:12) 
[GCC 3.4.3  (Gentoo Linux 3.4.3, ssp-3.4.3-0, pie-8.7.6.6)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import re
>>> whitespaceSplitter = re.compile("(\w+)")
>>> whitespaceSplitter.split("1 2  3   \t\n5")
['', '1', ' ', '2', '  ', '3', '   \t\n', '5', '']
>>> whitespaceSplitter.split(" 1 2  3   \t\n5 ")
[' ', '1', ' ', '2', '  ', '3', '   \t\n', '5', ' ']

Note the null strings at the beginning and end if there are no instances
of the split RE at the beginning or end. Pondering the second invocation
should show why they are there, though darned if I can think of a good way
to put it into words.