Efficiently split a string using multiple separators and retaining each separator?

Question

I need to split strings of data using each character from string.punctuation and string.whitespace as a separator.

Furthermore, I need for the

Answer 1

from string import punctuation, whitespace

s = "..test. and stuff"

f = lambda s, c: s + ' ' + c + ' ' if c in punctuation else s + c
l =  sum([reduce(f, word).split() for word in s.split()], [])

print l