标签：dict 自己 gen none res ack user sim 学习
1.Dictionary：Dictionary类型即字典，代表一个键/值存储库。
user_info = { "name": "simon", "age": "24", "gender": "M" } user_info.clear() print(user_info) #{}
copy()：复制字典的一个副本。
user_info = { "name": "simon", "age": "24", "gender": "M" } user_info1 = user_info.copy() print(user_info1) #{‘gender‘: ‘M‘, ‘name‘: ‘simon‘, ‘age‘: ‘24‘}
fromkeys(seq,val=None)：用seq中的元素作为键创建字典，所有键的值都设为val,val默认为None
user_info = { "name": "simon", "age": "24", "gender": "M" } user_info1 = user_info.fromkeys(["address", "school"], "hangzhou") print(user_info1) #{‘school‘: ‘hangzhou‘, ‘address‘: ‘hangzhou‘}
get(key,default=None)：读取字典中的键key，返回该键的值；如果找不到则返回default所设的值。
user_info = { "name": "simon", "age": "24", "gender": "M" } d = user_info.get(‘name‘, "button") d1 = user_info.get(‘name1‘, ‘button‘) print(d) #simon print(d1) #button
items()：返回一个包含字典中（键，值）对元组的列表。
keys()：返回一个字典中所有键的列表
user_info = { "name": "simon", "age": "24", "gender": "M" } for k, v in user_info.items(): print(k, v)
pop(key[,default])：读取某键的值，并从字典中删除该键的值。如果键key不存在且没有设置default，则引发KeyError异常
user_info = { "name": "simon", "age": "24", "gender": "M" } user_info.pop(‘name‘, ‘button‘) print(user_info) #{‘gender‘: ‘M‘, ‘age‘: ‘24‘}
setdefault(key,default=None)：设置字典中键key的值为default，类似get()
user_info = { "name": "simon", "age": "24", "gender": "M" } name = user_info.setdefault("name1", ‘button‘) print(name) #button print(user_info) #{‘name‘: ‘simon‘, ‘gender‘: ‘M‘, ‘age‘: ‘24‘, ‘name1‘: ‘button‘}
update(dict)：合并字典（批量更新字典）
user_info = { "name": "simon", "age": "24", "gender": "M" } #批量更新 test = { "a1": "123", "a2": "456", "a3": "789" } user_info.update(test) print(user_info) #{‘a2‘: ‘456‘, ‘a1‘: ‘123‘, ‘gender‘: ‘M‘, ‘a3‘: ‘789‘, ‘age‘: ‘24‘, ‘name‘: ‘simon‘}
4.del 删除元素
test = { "a1": "123", "a2": "456", "a3": "789" } #删除元素 del test["a1"] print(test) #{‘a2‘: ‘456‘, ‘a3‘: ‘789‘}
5.pop()删除指定key的元素
test = { "a1": "123", "a2": "456", "a3": "789" } test.pop("a1") print(test) #{‘a3‘: ‘789‘, ‘a2‘: ‘456‘}
6.popitem()从左边开始删除元素
test = { "a1": "123", "a2": "456", "a3": "789" } print(test) #{‘a1‘: ‘123‘, ‘a2‘: ‘456‘, ‘a3‘: ‘789‘} test.popitem() print(test) #{‘a2‘: ‘456‘, ‘a3‘: ‘789‘}
标签：dict 自己 gen none res ack user sim 学习
原文地址：http://www.cnblogs.com/SimonXu/p/7672769.html
