9.字典dic,dic = {'k1': "v1", "k2": "v2", "k3": [11,22,33]}
a.请循环输出所有的key

for i in dic.keys():
    print(i)

b.请循环输出所有的value

for i in dic.values():
    print(i)

c.请循环输出所有的key和value

for i,j in dic.items():
    print(i,j)

d.请在字典中添加一个键值对,"k4": "v4",输出添加后的字典

dic.setdefault('k4','v4')
print(dic)

e.请在修改字典中 "k1" 对应的值为 "alex",输出修改后的字典

dic['k1'] = 'alex'
print(dic)

f.请在k3对应的值中追加一个元素 44,输出修改后的字典

dic['k3'].append('44')
print(dic)

g.请在k3对应的值的第 1 个位置插入个元素 18,输出修改后的字典

dic['k3'].insert(0,18)
print(dic)