# a function to return the numeric content of a cost item
# for instance $12.99 or -$123456789.01 (deficit spenders)
def getVal(txt):
  if txt[0] == "$":    # remove leading dollar sign
    txt = txt[1:]
  if txt[1] == "$":    # could be -$xxx
    txt = txt[0] + txt[2:]
 
  while txt:           # select float or integer return
    try:
      f = float(txt)
      i = int(f)
      if f == i:
        return i
      return f
    except TypeError:  # removes possible trailing stuff  
        txt = txt[:-1]
  return 0
 
# test the function ...
print getVal('-$123.45')