第二十二天- 序列化 pickle json shelve

1 import pickle 2 3 4 class User: 5 def __init__(self,username,password): 6 self.username = username 7 self.password = password 8 9 10 class Client: 1 ...

# 序列化：存儲或傳輸數據時，把對象處理成方便存儲和傳輸的數據格式，這個過程即為序列化
# Python中序列化的三種方案：
#   1.pickle  python任意數據——》bytes寫入⽂件；寫好的bytes——》python的數據.
#   2.shelve  簡單另類的⼀種序列化⽅案. 可以作為⼀種⼩型的資料庫來使⽤
#   3.json    將字典列表轉換成字元串,前後端數據交互高頻使用的⼀種數據格式

# pickle：
# 寫入到文件的是bytes

# pickle中的dumps可以序列化⼀個對象.loads可以反序列化⼀個對象

 1 import pickle
 2 class Cat:
 3     def __init__(self,name,color):
 4         self.name = name
 5         self.color =color
 6 
 7     def chi(self):
 8         print("%s貓會吃老鼠"%(self.name))
 9 
10 c = Cat("加菲","橘色")
11 # c.chi()
12 bs = pickle.dumps(c)  # 把對象轉換成bytes
13 # print(bs)  # b'\x80\x03c__main__\nCat\nq\x00)\x81q\x01}q\x02(X\x04\x00\x00\x00nameq\x03X\x06\x00\x00\x00\xe5\x8a\xa0\xe8\x8f\xb2q\x04X\x05\x00\x00\x00colorq\x05X\x06\x00\x00\x00\xe6\xa9\x98\xe8\x89\xb2q\x06ub.'
14 
15 # 把bytes反序列化成對象
16 cc = pickle.loads(b'\x80\x03c__main__\nCat\nq\x00)\x81q\x01}q\x02(X\x04\x00\x00\x00nameq\x03X\x06\x00\x00\x00\xe5\x8a\xa0\xe8\x8f\xb2q\x04X\x05\x00\x00\x00colorq\x05X\x06\x00\x00\x00\xe6\xa9\x98\xe8\x89\xb2q\x06ub.')
17 cc.chi()
18 print(cc.name,cc.color)  # 加菲貓會吃老鼠  加菲 橘色


# dump load讀寫文件操作
# dump load ⼀個對象寫讀到文件

1 c = Cat("加菲","橘色")
2 pickle.dump(c,open("cat.dat",mode = 'wb'))  # 把對象寫到文件  pickle.dump() 註意bytes用wb模式
3 ccc = pickle.load(open('cat.dat',mode='rb'))  # 把對象讀取出來  pickle.load() 註意bytes用rb模式
4 ccc.chi()  # 加菲貓會吃老鼠
5 print(ccc.name,ccc.color)  # 加菲 橘色


# pickle用list讀寫多個對象

 1 c1 = Cat("加菲1","橘色")
 2 c2 = Cat("加菲2","橘色")
 3 c3 = Cat("加菲3","橘色")
 4 c4 = Cat("加菲4","橘色")
 5 c5 = Cat("加菲5","橘色")
 6 
 7 # lst = [c1,c2,c3,c4,c5]
 8 # f = open('cat.dat',mode='wb')
 9 # pickle.dump(lst,f)  # 把lst寫到f
10 
11 f = open('cat.dat',mode='rb')
12 lis = pickle.load(f)  # 把lis從f讀取出來
13 for cc in lis:
14     cc.chi()


# 應用：pickle實現註冊登錄

 1 import pickle
 2 
 3 
 4 class User:
 5     def __init__(self,username,password):
 6         self.username = username
 7         self.password = password
 8 
 9 
10 class Client:
11     # 註冊
12     def regist(self):
13         uname = input("請輸入你的賬戶：")
14         pwd = input("請輸入你的密碼：")
15         user = User(uname,pwd)  # 把uname pwd 傳參到User類
16         pickle.dump(user,open("userinfo",mode='ab'))  # 把對象保存到userinfo
17         print("註冊成功！")
18 
19     # 登錄
20     def login(self):
21         uname = input("請輸入你的賬戶：")
22         pwd = input("請輸入你的密碼：")
23         f = open('userinfo',mode='rb')  
24         while 1:
25             # 加入try except 當不存在的賬戶登錄時 拋出錯誤
26             try:
27                 u = pickle.load(f)  # 從userinfo中讀取出用戶 
28                 if u.username == uname and u.password == pwd:
29                     print("登陸成功！")
30                     break
31             except Exception as e:
32                 print("登錄失敗！")
33                 break
34 
35 d = Client()
36 # print("註冊")
37 # d.regist()
38 # d.regist()
39 # d.regist()
40 # print("登錄")
41 # d.login()
42 # d.login()
43 # d.login()

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# shelve 就是把數據寫到硬碟上.操作shelve非常的像操作字典.

1 import shelve
2 
3 d = shelve.open("test")  # 可理解成文件類型的字典
4 # d['wf'] = '汪峰'
5 d['wf'] = '王菲'
6 print(d['wf'])  # 汪峰  王菲
7 d.close()

# 存儲一些複雜點的數據

 1 import shelve
 2 d = shelve.open('test')
 3 d['wf'] = {'name':'汪峰','age':47,'wife':{'name':'章子怡','hobby':'拍電影'}}
 4 print(d['wf']) # 運行結果 {'name': '汪峰', 'age': 47, 'wife': {'name': '章子怡', 'hobby': '拍電影'}}
 5 d.close()
 6 
 7 # 嘗試修改
 8 d = shelve.open('test')
 9 d['wf']['wife']['name'] = '小章'
10 print(d['wf'])  # 運行結果 {'name': '汪峰', 'age': 47, 'wife': {'name': '章子怡', 'hobby': '拍電影'}}
11 d.close()
12 # 坑 由上可知 直接修改沒效果 需用到 writeback

# writeback=True 可動態的把修改的信息寫入到⽂件中.

1 d = shelve.open('test',writeback=True)  # 文件類型字典修改時 writeback 把修改回寫到文件
2 d['wf']['wife']['hobby'] = '搓麻將'  # 修改vlue
3 d.close()
4 
5 d = shelve.open('test')
6 print(d['wf'])  # 運行結果 {'name': '汪峰', 'age': 47, 'wife': {'name': '章子怡', 'hobby': '搓麻將'}}
7 d.close()

# json 前後端交互的紐帶

# json全稱javascript object notation.翻譯js對象簡譜.
# json代碼(python中的字典)

 1 wf = {
 2     "name":"汪峰",
 3     "age":18,
 4     "hobby":"上頭條",
 5     "wife":{
 6         "name":'⼦怡',
 7         "age":19,
 8         "hobby":["唱歌", "跳舞", "演戲"]
 9         }
10 }

# 直接把字典轉化成json字元串
import  json

1 dic = {'a':'一隻蘿莉','b':'兩隻蘿莉','c':'一群蘿莉','d':False,'e':None}
2 s = json.dumps(dic,ensure_ascii=False)  # ensure_ascii 固定套路不轉成bytes
3 print(type(s))  # <class 'str'>
4 print(s)  # {"a": "一隻蘿莉", "b": "兩隻蘿莉", "c": "一群蘿莉", "d": false, "e": null}

# 把json字元串轉換成字典

1 s1 = '{"a": "一隻蘿莉", "b": "兩隻蘿莉", "c": "一群蘿莉", "d": false, "e": null}'
2 d = json.loads(s1)
3 print(d)  # {'a': '一隻蘿莉', 'b': '兩隻蘿莉', 'c': '一群蘿莉', 'd': False, 'e': None}
4 print(type(d))  # <class 'dict'>

# 把json寫入文件

1 dic = {'a':'小蘿莉','b':'大蘿莉','c':'一群蘿莉','d':False,'e':None,'wf':{'name':'怒放的生命','hobby':'皮褲'}}
2 f = open('loli.json',mode='w',encoding='utf-8')  # 註意:utf-8格式寫入
3 json.dump(dic,f,ensure_ascii=False,indent=4)  # indent=4 縮進4格 等同tab 便於閱讀

# 文件中讀取json

1 f = open('loli.json',mode='r',encoding="utf-8")
2 d = json.load(f)
3 # print(d)
4 f.close()

# 把對象轉換成json

 1 class Person:
 2     def __init__(self,firstName,lastName):
 3         self.firstName = firstName
 4         self.lastName = lastName
 5 
 6 p = Person('尼古拉斯','趙四')
 7 
 8 # 方案一 轉化的是字典
 9 s = json.dumps(p.__dict__,ensure_ascii=False)
10 print(s)  # {"firstName": "尼古拉斯", "lastName": "趙四"}
11 
12 # 方案二 自己定義函數
13 def func(obj):
14     return {
15         'firstName':obj.firstName,
16         'lastName':obj.lastName
17     }
18 
19 s = json.dumps(p,default=func,ensure_ascii=False)
20 print(s)  # {"firstName": "尼古拉斯", "lastName": "趙四"}

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# 函數把字典(json)轉換成對象

1 s = '{"firstName": "尼古拉斯", "lastName": "趙四"}'
2 def func(dic):
3     return Person(dic['firstName'],dic['lastName'])
4 
5 p = json.loads(s,object_hook=func)  # 字典轉換成對象
6 
7 print(p.firstName,p.lastName)

# 註意.我們可以向同⼀個⽂件中寫⼊多個json串.但是讀不⾏.

 1 import json
 2 lst = [{'a':1},{'b':2},{'c':3}]
 3 f = open('test.json',mode='w',encoding='utf-8')
 4 for el in lst:
 5     json.dump(el,f)
 6 f.close()
 7 # 若需要讀取改用 dumps和loads  迴圈對每行分別處理
 8 import json
 9 lst = [{"a": 1}, {"b": 2}, {"c": 3}]
10 # 寫⼊
11 f = open("test.json", mode="w", encoding="utf-8")
12 for el in lst:
13     s = json.dumps(el, ensure_ascii=True) + "\n"  # 註意dumps這裡ensure_ascii是True
14     f.write(s)
15 f.close()
16 # 讀取
17 f = open("test.json", mode="r", encoding="utf-8")
18 for line in f:
19     dic = json.loads(line.strip())
20     print(dic)
21 f.close()

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# configparser模塊(參考)
# 模塊用於配置⽂件格式與windows ini⽂件類似,可以包含⼀個或多個節(section)每個節可有多個參數(鍵=值)

# 伺服器配置文件

 1 '''
 2 [DEFAULT] [DEFAULT]
 3 ServerAliveInterval = 45
 4 Compression = yes
 5 CompressionLevel = 9
 6 ForwardX11 = yes
 7 [[bitbucket.org bitbucket.org]]
 8 User = hg
 9 [[topsecret.server.com topsecret.server.com]]
10 Port = 50022
11 ForwardX11 = no
12 '''

# ⽤configparser對這樣的⽂件進⾏處理
# 初始化

 1 import configparser
 2 
 3 config = configparser.ConfigParser()
 4 config['DEFAULT'] = {
 5 "sleep": 1000,
 6  "session-time-out": 30,
 7  "user-alive": 999999
 8 }
 9 config['TEST-DB'] = {
10  "db_ip": "192.168.17.189",
11  "port": "3306",
12  "u_name": "root",
13  "u_pwd": "123456"
14 }
15 config['168-DB'] = {
16  "db_ip": "152.163.18.168",
17  "port": "3306",
18  "u_name": "root",
19  "u_pwd": "123456"
20 }
21 config['173-DB'] = {
22  "db_ip": "152.163.18.173",
23  "port": "3306",
24  "u_name": "root",
25  "u_pwd": "123456"
26 }
27 f = open("db.ini", mode="w")
28 config.write(f) # 寫⼊⽂件
29 f.flush()
30 f.close()

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# 讀取文件信息

 1 config = configparser.ConfigParser()
 2 config.read("db.ini") # 讀取⽂件
 3 print(config.sections()) # 獲取到section. 章節...DEFAULT是給每個章節都配備的信息
 4 print(config.get("DEFAULT", "SESSION-TIME-OUT")) # 從xxx章節中讀取到xxx信息
 5 # 也可以像字典⼀樣操作
 6 print(config["TEST-DB"]['DB_IP'])
 7 print(config["173-DB"]["db_ip"])
 8 for k in config['168-DB']:
 9  print(k)
10 for k, v in config["168-DB"].items():
11  print(k, v)
12 print(config.options('168-DB')) # 同for迴圈,找到'168-DB'下所有鍵
13 print(config.items('168-DB')) #找到'168-DB'下所有鍵值對
14 print(config.get('168-DB','db_ip')) # 152.163.18.168 get⽅法Section下的key對應的value

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# 增刪改操作
# 先讀取. 然後修改. 最後寫回⽂件

 1 config = configparser.ConfigParser()
 2 config.read("db.ini") # 讀取⽂件
 3 # 添加⼀個章節
 4 # config.add_section("189-DB")
 5 # config["189-DB"] = {
 6 # "db_ip": "167.76.22.189",
 7 # "port": "3306",
 8 # "u_name": "root",
 9 # "u_pwd": "123456"
10 # }
11 # 修改信息
12 config.set("168-DB", "db_ip", "10.10.10.168")
13 # 刪除章節
14 config.remove_section("173-DB")
15 # 刪除元素信息
16 config.remove_option("168-DB", "u_name")
17 # 寫回⽂件
18 config.write(open("db.ini", mode="w"))

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