import re
s = "one two 3.4 5,6 seven.eight nine,ten"
print re.split('\s|(?<!\d)[,.](?!\d)', s)
aW1wb3J0IHJlCgpzID0gIm9uZSB0d28gMy40IDUsNiBzZXZlbi5laWdodCBuaW5lLHRlbiIKcHJpbnQgcmUuc3BsaXQoJ1xzfCg/PCFcZClbLC5dKD8hXGQpJywgcyk=
['one', 'two', '3.4', '5,6', 'seven', 'eight', 'nine', 'ten']