Python——day03

字典：

!/usr/bin/env python
-*- encoding:UTF-8 -*-


字典
dict
# # # 字典的value可以是任何值  字典无序
info = {
    "k1": "v1",  # 键值对
    "k2": "v2",
    "k3": [
        11,
        22,
        33,
        [12, 12],
        {
            "kk1": "vv1",
            "kk2": (11, 33,),

        }
    ],
    "k4": (11, 22, 33, 44,)
}
print(info)

# # # 列表和字典不可以作为key值，元组可以
info = {
    123: 'jfdsl',
    "K1": 'fjd;a',
    (11, 22): 123
}
print(info)

# 索引查找指定元素
v = info["k1"]
print(v)
v = info[2]
print(v)
v = info["k3"][4]["kk2"][0]

# 删除指定元素
del info["k3"][4]["kk1"]

# 循环只有for
info = {
    "k1": "v1",  # 键值对
    "k2": "v2",
    "k3": [
        11,
        22,
        33,
        [12, 12],
        {
            "kk1": "vv1",
            "kk2": (11, 33,),

        }
    ],
    "k4": (11, 22, 33, 44,)
}
# 默认输出key
for item in info:
    print(item)
for item in info.keys():
    print(item)

for item in info.values():
    print(item)

for item in info.keys():
    print(item, info[item])

for key, val in info.items():
    print(key, val)

# 布尔值可以为key,True代表1，False代表0，在字典中重复key会被覆盖
info = {
    1:"jfdkl",
    True:1234,
    0: "jfdkla;"
}
print(info)


# # # # # # #特有的

dic = {
    "k1": "v1",
    'k2': 124
}
# 根据系列，创建字典，并指定统一的值，
v = dict.fromkeys(["k1",1234,"555"],123)
print(v)
# 根据key获取值，不存在，输出默认值
v = dic.get("K111",1111)
print(v)

删除并获取值
v = dic.pop('k1')
print(dic, v)
k,v = dic.pop('k1', 90)
print(dic, v1)
k,v = dic.popitem()
print(dic, k, v)


# 设置值
# 已存在，不设置，获取当前key对应的值
# 不存在，设置，获取当前key对应的值
dic = {
    "k1": "v1",
    'k2': 124
}

v = dic.setdefault("k1798","123")
print(dic,v)

dic = {
    "k1": "v1",
    'k2': 124
}
dic.update({'k1': '112231','k3':123456})
print(dic)
dic.update(k1=1244312,k3=14312,k5="dksa")
print(dic)

keys() values() items() get uodate

 

dict.fromkeys　　.pop　　.setdefault　　keys()　　values()　　items()　　get　　uodate