関連ワード:  python sort list of tuples    python sort list of tuples by second element    python sort list of tuples by first element    python sort list of tuples by first then second element    python sort list of tuples by second element descending    python sort list of tuples by key    python sort list of tuples based on first element    python sort list of tuples by both elements    python sort list of tuples by two elements    python sort list of tuples by value