序列化与反序列化二json

json格式的数据,所有的编程语言都能识别,本身是字符串
类型有要求: int float bool str list tuple dict None

json与pickle的应用场景分别是什么?

json 主要应用于传输数据 , 序列化成字符串
pickle 主要应用于存储数据 , 序列化成二进制字节流

# json 基本用法
# json =>  dumps 和 loads
"""ensure_ascii=False 显示中文 sort_keys=True 按键排序"""
dic = {"name":"梁新宇","sex":"野味","age":22,"family":["爸爸","妈妈","姐姐"]}
res = json.dumps(dic,ensure_ascii=False,sort_keys=True)
print(res , type(res))

dic = json.loads(res)
print(dic , type(dic))


# json => dump 和 load
with open("lianxi3.json",mode="w",encoding="utf-8") as fp:
    json.dump(dic,fp,ensure_ascii=False)
with open("lianxi3.json",mode="r",encoding="utf-8") as fp:
    dic = json.load(fp)
print(dic , type(dic))

# ### json 和 pickle 之间的区别
# 1.json
# json 连续dump数据 , 但是不能连续load数据  , 是一次性获取所有内容进行反序列化.
dic1 = {"a":1,"b":2}
dic2 = {"c":3,"d":4}
with open("lianxi4.json",mode="w",encoding="utf-8") as fp:
    json.dump(dic1,fp)
    fp.write("\n")
    json.dump(dic2,fp)
    fp.write("\n")

# 不能连续load,是一次性获取所有数据 , error
"""
with open("lianxi4.json",mode="r",encoding="utf-8") as fp:
    dic = json.load(fp)
"""

# 解决办法 loads(分开读取)
with open("lianxi4.json",mode="r",encoding="utf-8") as fp:
    for line in fp:
        dic = json.loads(line)
        print(dic,type(dic))


# 2.pickle
import pickle
# pickle => dump 和 load
# pickle 连续dump数据,也可以连续load数据
with open("lianxi5.pkl",mode="wb") as fp:
    pickle.dump(dic1,fp)
    pickle.dump(dic2,fp)
    pickle.dump(dic1,fp)
    pickle.dump(dic2,fp)
    

# 方法一
"""
with open("lianxi5.pkl",mode="rb") as fp:
    dic1 = pickle.load(fp)
    dic2 = pickle.load(fp)
    print(dic1)
    print(dic2)
"""
# 方法二 (扩展)
"""try .. except .. 把又可能报错的代码放到try代码块中,如果出现异常执行except分支,来抑制报错"""
# 一次性拿出所有load出来的文件数据
try:
    with open("lianxi5.pkl",mode="rb") as fp:
        
        while True:
            dic = pickle.load(fp)
            print(dic)
except:
    pass

json 和 pickle 两个模块的区别?
(1)json序列化之后的数据类型是str,所有编程语言都识别,
但是仅限于(int float bool)(str list tuple dict None)
json不能连续load,只能一次性拿出所有数据
(2)pickle序列化之后的数据类型是bytes,用于数据存储
所有数据类型都可转化,但仅限于python之间的存储传输.
pickle可以连续load,多套数据放到同一个文件中