def _get_conversion_multiplier(big_unit_code, small_unit_code):
 if (big_unit_code == 14):
  return 1
 c = big_unit_code
 factor = 1
 while (c < small_unit_code):
  try:
   (c, mult) = _factors[c]
  except KeyError:
   return None
  factor *= mult
 if (c == small_unit_code):
  return factor
 else:
  return None

def _get_conversion_multiplier ( big_unit_code , small_unit_code ) : if ( big_unit_code == 14 ) : return 1 c = big_unit_code factor = 1 while ( c < small_unit_code ) : try : ( c , mult ) = _factors [ c ] except KeyError : return None factor *= mult if ( c == small_unit_code ) : return factor else : return None
return an integer multiplier allowing to convert from *big_unit_code* to *small_unit_code* .