1. list 脚标
li = [1,2,3,[1,2,['ab','cd'],'wang'],'wo'] w = li[3][2][1][0] print(w) ———————— c
2. list 循环
li = [1,2,3,[1,2,['ab','cd'],'wang'],'wo'] s = '' for i in li: s += str(i) print(s) ———————— 123[1, 2, ['ab', 'cd'], 'wang']wo