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('')
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)