018_序列化模块_什么是模块

dic = {"k1":‘v1‘}
print(type(dic),dic)
import json
str_d = json.dumps(dic)     #序列化    #>>>
print(type(str_d),str_d)
dic_d = json.loads(str_d)   #反序列化   #>>>
print(type(dic_d),dic_d)

import json
dic = {1:"a",2:‘b‘}
f = open(‘fff‘,‘w‘,encoding=‘utf-8‘)
json.dump(dic,f)
f.close()
f = open(‘fff‘)
res = json.load(f)
f.close()
print(type(res),res)

import json
dic = {1:"中国",2:‘b‘}
f = open(‘fff‘,‘w‘,encoding=‘utf-8‘)
json.dump(dic,f,ensure_ascii=False)   #要加入ensure_ascii=False，不然会写入bytes类型
f.close()
f = open(‘fff‘,encoding=‘utf-8‘)
res = json.load(f)
f.close()
print(type(res),res)

# import json
# json dump load
# dic = {1:"中国",2:‘b‘}
# f = open(‘fff‘,‘w‘,encoding=‘utf-8‘)
# json.dump(dic,f,ensure_ascii=False)
# json.dump(dic,f,ensure_ascii=False)
# f.close()
# f = open(‘fff‘,encoding=‘utf-8‘)
# res1 = json.load(f)
# res2 = json.load(f)
# f.close()
# print(type(res1),res1)
# print(type(res2),res2)

# json
# dumps {} -- >为了分次写将其写入成一行一行的dumps ‘{}\n‘
# 一行一行的读
# ‘{}\n‘
# ‘{}‘ loads

l = [{‘k‘:‘111‘},{‘k2‘:‘111‘},{‘k3‘:‘111‘}]
f = open(‘file‘,‘w‘)
import json
for dic in l:
    str_dic = json.dumps(dic)
    f.write(str_dic+‘\n‘)
f.close()
f = open(‘file‘)
import json
l = []
for line in f:
    dic = json.loads(line.strip())
    l.append(dic)
f.close() 
print(l)

import pickle
dic = {‘k1‘:‘v1‘,‘k2‘:‘v2‘,‘k3‘:‘v3‘}
str_dic = pickle.dumps(dic)
print(str_dic)  #一串二进制内容
dic2 = pickle.loads(str_dic)
print(dic2)    #字典

import time
struct_time1  = time.localtime(1000000000)
struct_time2  = time.localtime(2000000000)
f = open(‘pickle_file‘,‘wb‘)
pickle.dump(struct_time1,f)
pickle.dump(struct_time2,f)
f.close()
f = open(‘pickle_file‘,‘rb‘)
struct_time1 = pickle.load(f)
struct_time2 = pickle.load(f)
print(struct_time1.tm_year)
print(struct_time2.tm_year)
f.close()

import shelve
f = shelve.open(‘shelve_file‘)
f[‘key‘] = {‘int‘:10, ‘float‘:9.5, ‘string‘:‘Sample data‘}  #直接对文件句柄操作，就可以存入数据
f.close()
import shelve
f1 = shelve.open(‘shelve_file‘)
existing = f1[‘key‘]  #取出数据的时候也只需要直接用key获取即可，但是如果key不存在会报错
f1.close()
print(existing)

import shelve
#修改不会保存
f1 = shelve.open(‘shelve_file‘)
print(f1[‘key‘])
f1[‘key‘][‘new_value‘] = ‘this was not here before‘
f1.close()
#修改会保存
f2 = shelve.open(‘shelve_file‘, writeback=True)
print(f2[‘key‘])
f2[‘key‘][‘new_value‘] = ‘this was not here before‘
f2.close()

import demo
def read():
    print(‘my read func‘)
demo.read()
print(demo.money)

import sys
print(sys.modules.keys())
print(sys.path)

import time as t   #将time模块命名为t
print(t.time())

oracle
mysql
if 数据库 == ‘oracle’：
    import oracle as db
elif 数据库 == ‘mysql’：
    import mysql as db
#两个数据图库都有 connect方法
#就都可以用 db.connect 调用
#想要操作数据库就要：
# 连接数据库   db.connect
# 登录认证
# 增删改查
# 关闭数据库

from time import sleep

from demo import read
def read():
    print(‘my read‘)
read()

if __name__ == ‘__main__‘
   pass