def _extract(key, start, length):
 k = key[start:(start + length)]
 return reduce((lambda x, y: (((x * 2) + ord(y)) - 48)), k, 0)

def _extract ( key , start , length ) : k = key [ start : ( start + length ) ] return reduce ( ( lambda x , y : ( ( ( x * 2 ) + ord ( y ) ) - 48 ) ) , k , 0 )
get an item from a dictionary .