Python零基础入门 -- 字典操作与应用

字典dict 列表list 元组 tuple 集合set

字典定义格式{} dict()

{key1:value1,key2:value2}

key 键值必须唯一

key 字符串 数字 元组

my_dict={"name":"tom"}

print(my_dict)

增删改查

#字典新增 修改元素

my_dict["gender"]="man"

#健同名 会出现覆盖

my_dict["name"]="bobo"

ctrl / 快捷注释

#更新update

my_dict.update({"name":"lucky","height":180})

print(my_dict)

字典删除

my_dict.pop("height")

del my_dict["name"]

清空数据

my_dict={}

print(my_dict)

查询

dict_query={"name":"lucky","height":180}

print(dict_query["name"])

print(my_dict['gender'])

"""
演练1.查询字典找那个每个元素的键与值
"""

for key in dict_query:

# print(key,dict_query[key])

print(dict_query.keys())
print(dict_query.values())
print(dict_query.items())
print(list(dict_query.keys()))

压缩

key_list=["name","age","id"]
value_list=['Arven','10','1']

print(zip(key_list,value_list))

print(dict(zip(key_list,value_list)))

字典嵌套使用

查询每次考试成绩大于等于90分的科目、分数、第几次考试、名称

stuent_info = {
"name":'张三',
"gender":"man",
"age":"18",
"score":{
"chinese":[66,77,88],
"Math":[78,88,98],
"English":[80,90,100]
},
"ranking":{
"first":15,
"second":10,
"thirdly":5
},
}

获取第二次英文成绩 有5个元素

print(stuent_info["score"]['English'][1])