因为比较浅显易懂，所以直接上代码。
1. clear
a = {"A": {"male": "18"}}
a.clear()
print(a)
- 输出结果
>>> {}
2. copy
dict类型内置拷贝方法为浅拷贝
- 输出结果
a = {"A": {"male": "18"}}
b = a.copy()
b["A"]["male"] = ["19"]
print(a)
print(b)
- 输出结果
>>>{'A': {'male': ['19']}}
>>>{'A': {'male': ['19']}}
3.静态方法 -fromkeys
将可迭代对象中的每一个元素作为字典的键，并将值设置为传入参数
new_list = ["C", "D"]
new_dict = dict.fromkeys(new_list, ["female", "20"])
print(new_dict)
- 输出结果
>>>{'C': ['female', '20'], 'D': ['female', '20']}
4. get
在字典中查找值，如果没有返回None
# get 查找键
a = {"A": {"male": "18"}}
print(a.get("B"))
print(a.get("A"))
- 输出结果
>>>None
>>>{'male': '18'}
5. items
遍历字典中的每一组键和值
new_list = ["C", "D"]
new_dict = dict.fromkeys(new_list, ["female", "20"])
for key, value in new_dict.items():
print(key, value)
- 输出结果
>>>C ['female', '20']
>>>D ['female', '20']
6. setdefault
在原字典中追加添加数据并返回追加的数据
new_list = ["C", "D"]
new_dict = dict.fromkeys(new_list, ["female", "20"])
default_value = new_dict.setdefault("B", {"male": "21"})
print(new_dict)
print(default_value)
- 输出结果
>>>{'C': ['female', '20'], 'D': ['female', '20'], 'B': {'male': '21'}}
>>>{'male': '21'}
7. update
在原字典中追加新数据
new_list = ["C", "D"]
new_dict = dict.fromkeys(new_list, ["female", "20"])
# 方式一 : key=value
new_dict.update(E={"female": "25"}, F={"female": "26"})
print(new_dict)
# # 方式二 :list 嵌套tuple ，如：[(key, v)]
new_dict.update([("G",{"male": "23"})])
print(new_dict)
- 返回结果
>>>{'C': ['female', '20'], 'D': ['female', '20'], 'E': {'female': '25'}, 'F': {'female': '26'}}
{'C': ['female', '20'], 'D': ['female', '20']
>>> 'E': {'female': '25'}, 'F': {'female': '26'}, 'G': {'male': '23'}, 'H': {'female': '17'}}
