import re;
input = '1. List item #1, 2. List item 2, 3. List item #3.';
lines = re.split('(?:^|, )\d{1,2}\. ', input);
if lines[0] == '':
lines = lines[1:];
print lines;
aW1wb3J0IHJlOwoKaW5wdXQgPSAnMS4gTGlzdCBpdGVtICMxLCAyLiBMaXN0IGl0ZW0gMiwgMy4gTGlzdCBpdGVtICMzLic7CmxpbmVzID0gcmUuc3BsaXQoJyg/Ol58LCApXGR7MSwyfVwuICcsIGlucHV0KTsKaWYgbGluZXNbMF0gPT0gJyc6CiAgbGluZXMgPSBsaW5lc1sxOl07CnByaW50IGxpbmVzOw==