python学习第八讲,python中的数据类型,列表,元祖,字典,之字典使用与介绍

xiaoming = {"name": "小明",
            "age": 18,
            "gender": True,
            "height": 1.75}

In [1]: xiaoming.
xiaoming.clear       xiaoming.items       xiaoming.setdefault
xiaoming.copy        xiaoming.keys        xiaoming.update
xiaoming.fromkeys    xiaoming.pop         xiaoming.values
xiaoming.get         xiaoming.popitem    

datadict  = {1 : "小明",
             "age" : 18,};

print(datadict[Key]);  取值,取值的时候,也是索引使用.不过索引是我们的key,比如我们的key是1,那么就是1
print(datadict["age"]); 输入的是key,不是索引. key当索引取寻找值.

修改:
datadict[key] = value;  语法
datadict["age"] = 10;   将age的value,修改为10

删除
datadict.pop(key); 方法pop删除.给一个key

len()函数.可以统计字典中键值对的属相.
value = len(dict);

合并字典
update(字典对象); 方法update 如果有两个相同的key合并.会覆盖原有的键值对.

tempdict = {1 : 2,};
dict.update(tempdict); 把tempdict合并到dict中.

清空
clear()函数.
dict.clear(字典对象);

# for 循环内部使用的 `key 的变量` in 字典
for key in 字典对象:

    print("%s: %s" % (k, 字典对象[key]))

card_list = [{"name": "张三",
              "qq": "12345",
              "phone": "110"},
             {"name": "李四",
              "qq": "54321",
              "phone": "10086"}
             ]

for i in card_list:
    for key in i :
       xxxx

card_list = [{"name": "张三",
              "qq": "12345",
              "phone": "110"},
             {"name": "李四",
              "qq": "54321",
              "phone": "10086"}
             ]
for dict in card_list :
    for key in dict:
        print("key = %s Value = %s " %(key,dict[key]));