★遍历字典dic�onary ①遍历key dictx = {"k1": "v1", "k2": "v2", "k3": "v3"} for key in dictx.keys(): print(key, "-------->", dictx[key]) ②遍历value dictx = {"k1": "v1", "k2": "v2", "k3": "v3"} for value in dictx dictx.values(): print(value) ③遍历item dictx = {"k1": "v1", "k2": "v2", "k3": "v3"} for k, v in dictx.items(): print(k, "---->", v) ★list/set/dic�onary增删改查操作 ①list数据操作（有序，数值可重复） listxx.append(x) #添加多个键值对，lx为另一 dictionary value2 = dictxx["k2"] # 取指定key对应的值 k,v=dictxx.popitem() # 随机返回并删除一个键值对 del dictxx["k2"] # 删除指定key的这对键值对 ★string和bytes转换