code: def bytes_from_readable_size(C, size, suffix='B'):
          
          s = re.split("^([0-9\.]+)\s*([%s]?)%s?" % (''.join(C.SIZE_UNITS), suffix), size, flags=re.I)
          bytes, unit = round(float(s[1])), s[2].upper()
          while unit in C.SIZE_UNITS and C.SIZE_UNITS.index(unit) > 0:
              bytes *= 1024
              unit = C.SIZE_UNITS[C.SIZE_UNITS.index(unit) - 1]
          return bytes
docs: given a readable_size (as produced by File.readable_size()), return the number of bytes.