字典的小知识
dic = {"name": "tom", "age": 23, "price": 110}
# 01：提取键值
print("1>>", dic["name"],type(dic["name"])) # 1>> tom <class 'str'>
print("2>>", dic.get("name")) # 1>> tom
print("3>>", dic.get("n"),type(dic.get("n"))) # 3>> None <class 'NoneType'>
# 02:判断键或值是否存在
print('name' in dic) #True
print('tom' in dic) #False
print('n' in dic) #False
# 03：设定指定字段值
dic['name']="jack"
print(dic) #{'name': 'jack', 'age': 23, 'price': 110}
print(dic['name']) # jack
# 04:访问所有键和值
# 1:提取所有的键
print(dic.keys()) # dict_keys(['name', 'age', 'price'])
print(type(dic.keys())) # <class 'dict_keys'>
# 2：提取所有的值
print(dic.values()) # dict_values(['tom', 23, 110])
print(type(dic.values())) # <class 'dict_values'>
for key, value in dic.items():
print(">>", key, value)
>> name tom
>> age 23
>> price 110