标签：print 返回 函数 obb 不可 设定 形式 查找 get
字典是python中唯一的映射类型，采用键值对（key-value）的形式存储数据。python对key进行哈希函数运算，根据计算的结果决定value的存储地址，所以字典是无序存储的，且key必须是可哈希的。可哈希表示key必须是不可变类型，如：数字、字符串、元组。
加入列表
dic = {‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
dic[‘li‘] = [‘a‘]
print(dic)
#输出
{‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘, ‘li‘: [‘a‘]}
无则添加
dic = {‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
dic[‘high‘]=185
print(dic)
#输出
{‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘, ‘high‘: 185}
有则覆盖
dic = {‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
dic[‘name‘]=‘Delaiesi‘
print(dic)
#输出
{‘name‘: ‘Delaiesi‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
setdefault
有键值对不作任何改变，没有才添加
dic = {‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
dic.setdefault(‘weight‘，180)
print(dic)
#输出
{‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘, ‘weight‘: 180}
pop pop根据key删除键值对，并返回对应的值，如果没有key则返回默认返回值
dic = {‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
dic_pop=dic.pop(‘name‘)
print(dic_pop)
print(dic)
#输出
Alisita
{‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
popitem 随机删除字典中的某个键值对，将删除的键值对以元祖的形式返回
dic = {‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
dic_pop=dic.popitem()
print(dic_pop)
print(dic)
#输出
(‘hobbie‘, ‘run‘)
{‘name‘: ‘Alisita‘, ‘age‘: ‘45‘}
clear 清空字典中的元素
dic = {‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
dic.clear()
print(dic)
#输出
{}
将dic所有的键值对覆盖添加（相同的覆盖，没有的添加）到dic1中
dic = {‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
dic1 = {‘name‘: ‘Aoraf‘, ‘sex‘: ‘male‘}
dic1.update(dic)
print(dic)
print(dic1)
#输出
{‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
{‘name‘: ‘Alisita‘, ‘sex‘: ‘male‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
dic = {‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
name = dic[‘name‘]
print(name)
#输出
Alisita
get dic.get(‘要查找的元素‘，设定的返回值) #如果字典中没有要找的项，则返回设定的返回值，若果没有设定返回值，则返回，默认返回值
dic = {‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
name = dic.get(‘sex‘,0)
print(name)
#输出
0
dic = {‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
name = dic.get(‘name‘,0)
print(name)
#输出
Alisita
dic = {‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
for item in dic.items():
print(item)
#items : ‘name‘: ‘Alisita‘
#keys :‘name‘
#values :‘Alisita‘
字典的循环
dic = {‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
for key in dic:
print(key)
#输出
name
age
hobbie
dic = {‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
for item in dic.items():
print(item)
#输出
(‘name‘, ‘Alisita‘)
(‘age‘, ‘45‘)
(‘hobbie‘, ‘run‘)
dic = {‘name‘: ‘Alisita‘, ‘age‘: ‘45‘, ‘hobbie‘: ‘run‘}
for key,value in dic.items():
print(key,value)
#输出
name Alisita
age 45
hobbie run
标签：print 返回 函数 obb 不可 设定 形式 查找 get
原文地址：https://www.cnblogs.com/albatorss/p/9372056.html
