listspam.py

from pyparsing import Forward, Word, nums, delimitedList, Optional, StringStart, StringEnd, Group, Literal
list = Forward()
expr = Word(nums)("multiplier") + Group(Literal('(').suppress() + list + Literal(')').suppress())("list")
list << delimitedList(Group(expr) | Word(nums)("rawnum"))
prog = StringStart() + list + StringEnd()
print list.parseString("1,2,3")
print prog.parseString("1,2,3")
info = prog.parseString("5(1,2,3(1,2))")
print info

def handle(matches):
   str = ""
   for match in matches:
      if isinstance(match,basestring):
          str+= match
      else:
          mult = match["multiplier"]
          list = match["list"]
          str+= (handle(list) * int(mult))
   return str

print handle(info)