标签：tab dde 二分查找 关系 ash weight already 数据类型 div
数据类型分为：可变数据类型，不可变数据类型
dic key:必须为可哈希数据类型，不可以变数据类型
value：任意数据类型
dic 优点：二分查找，存储大量关系型数据
dic特点：3.6以前无序，3.6后有序
dic = { ‘name‘: [‘bear‘, ‘Honey‘, ‘bee‘], ‘myPthon‘: [{‘num1‘: 71, ‘avg_age‘: 18} ,{‘num1‘: 71, ‘avg_age‘: 18} ,{‘num1‘: 71, ‘avg_age‘: 18}], True: 1, (1, 2, 3): ‘bee‘, 2: ‘Honey‘ } print(dic)
The key value is an immutable type(hash),which can be tuple,bool,int,str. (immutable：不可变)
But when the key value is a tuple, it must be an immutable type.
A varable tuple like this is not posible:(1, 2, 3, [1, 2]).
It will reopot errors:TypeError: unhashable type: ‘list‘.
dic1 = {‘age‘: 18, ‘name‘: ‘bear‘, ‘sex‘: ‘male‘}
dic2 = {}
# if the key value does not exist to be added to the dictionary
dic1[‘high‘] = 185
# if the dictionary has a key value, update the corresponding value to the dictionary (corresponding:相符的)
dic1[‘age‘] = 15
# Key value does not exist, default add none to dictionary
dic1.setdefault(‘weight‘)
# The key value does note exist, if the second parameter is specified,add the (key,value) pair to the dictionary
dic1.setdefault(‘weight‘, 90)
# If the key value already exists,the specified value will not be update to the dictionary
dic1.setdefault(‘name‘, ‘bee‘)
标签：tab dde 二分查找 关系 ash weight already 数据类型 div
原文地址：https://www.cnblogs.com/zxw-xxcsl/p/11478580.html
