test.py

#!/usr/local/bin/python
"""
If we apply a way like this to add functions to parse the strings, not only for
subjects but for other types we can have a lot more flexibility to decide our
parsing functions and to apply different parsings more easily and decide wich
is better
"""

import string
import re
from functools import partial

subject = 'HoLAS Chi3242Cos...'
PARSINGS = (string.lower, partial(re.sub, pattern=r'\W', repl=' ', none='string', count=re.U),
        partial(re.sub, pattern=r'\d', repl=' ', none='string', count=re.U), string.split)

for func in PARSINGS:
    if type(func) == partial:
        subject = func(**{func.keywords.pop('none'): subject})  # This is a little hack so we can name the keyword argument as we want to
    else:
        subject = func(subject)
print subject