~~~ for x in xxx: pass for x, y in xxx: pass ~~~ 序列 获取 key、value -------------------- str/list/tuple： ~~~ for i in l: print(i, l.index(i)) for i in range(len(l)): print(i, l[i]) for i, val in enumerate(l): print(i, val) ~~~ dict 获取 key、value ----------------------- ~~~ for k in d: print(k, d[k]) for v in d.values(): print(v) for k, v in d.items(): print(k, v) ~~~ set 没必要获取下标，因为其本身铁定无序。