Python 第十七章 序列化+os+sys+hashlib+collections

序列化

# 什么是序列化 -- json
# lit = [1,22,3,3,45]  # [1,22,3,3,45]
# s_lst = str(lit)
# print(s_lst,type(s_lst))
# print(list(s_lst))
# print(eval(s_lst))  # 禁止使用

import json
# 两组4个方法:
#     1.dumps loads
            # lit = [1,22,3,3,45]
            # print(json.dumps(lit),type(json.dumps(lit)))
            # str_lst = json.dumps(lit)
            # lst = json.loads(str_lst)
            # print(lst,type(lst))

            # dumps 将对象转换(序列化)成字符串
            # loads 将字符串转换(反序列化)成对象

            # dic = {'username':'宝元'}
            # str_dic = json.dumps(dic)  # 序列化
            # str_dic = json.dumps(dic,ensure_ascii=False)  # ensure_ascii=False 关闭ascii码
            # print(str_dic,type(str_dic))
            # dic1 = json.loads(str_dic)  # 反序列化
            # print(dic1,dic1["username"])

#     2.dump load
            # import json
            # lit = [1,22,3,3,45]
            # 同时写多个内容 进行序列化
            # lst = [1,2,3,4,56,]
            # f = open("info","w",encoding="utf-8")
            # f.write(json.dumps(lst) + "
")
            # f.write(json.dumps(lst) + "
")
            # f.write(json.dumps(lst) + "
")
            # f.write(json.dumps(lst) + "
")
            # f.write(json.dumps(lst) + "
")
            # f.close()

            # dump: 将对象转换(序列化)成字符串,写入文件
            # load: 将文件中字符串转换(反序列)成对象

            # 同时读多个内容进行反序列
            # f1 = open("info","r",encoding="utf-8")
            # for i in f1:
            #     l = json.loads(i)
            #     print(l)
            # f1.close()

# pickle 序列化 - nb(python所有对象进行转换)
# python自带的(只有python可以用)
# 两组4个方法:
#1. dumps loads
        # import pickle

        # lst = [12,3,4,5,768]
        # t_list = pickle.dumps(lst) # 转换成类似字节
        # print(t_list)
        # print(pickle.loads(t_list)[-1])

        # dic = {"user":"郭宝元"}
        # t_list = pickle.dumps(dic) # 转换成类似字节
        # print(t_list)
        # print(pickle.loads(t_list))

        # def func():
        #     print(111)

        # import json
        # fun = json.dumps(func)
        # print(fun)

        # fun = pickle.dumps(func)
        # print(fun)
        # pickle.loads(fun)()

#2. dump  load
# import pickle
# dic = {"usern":"baoyuian"}
# dic = {"usern":"宝元"}
# pickle.dump(dic,open("info","wb"))
# print(pickle.load(open("info","rb")))

# import pickle
# dic = {"user":"123"}
# pickle.dump(dic,open("info","ab"))

# import pickle
# dic = {"1":2}
# f = open("info","wb")
# s = "
".encode("utf-8")
# f.write(pickle.dumps(dic)+ s)
# f.write(pickle.dumps(dic)+ s)
# f.write(pickle.dumps(dic)+ s)
# f.close()
#
# f1 = open("info","rb")
# for i in f1:
#     print(pickle.loads(i))

# 推荐使用json
#   json是各种语言通用的
#   pickle(python私有)
# asdfasd

os

# os 模块 -- 程序员通过python向操作系统发送指令(与操作系统交互的接口)
# os模块四组:
#     1.工作目录
            # import os
            # print(os.getcwd()) # 当前工作路径  ***
            # os.chdir("F:s24day06") # 路径切换
            # print(os.curdir)  # 当前
            # print(os.pardir)  # 父级

#     2.文件夹
            # import os
            # os.mkdir("ttt") # 创建一个文件夹  ***
            # os.rmdir("ttt") # 删除一个文件夹  ***
            # os.makedirs("ttt/sss/ddd/ee")  # 递归创建文件夹     ***
            # os.removedirs("ttt/sss/ddd/ee")  # 递归删除文件夹   ***
            # print(os.listdir(r"F:s24day17"))  ***

#     3.文件
            # import os
            # os.rename()  # 修改名字   ***
            # os.remove("info") # 删除文件  ***

#     4.路径
            import os
            # print(os.path.abspath(r"01 今日内容.py"))  # 通过相对路径获取绝对路径  ***
            # print(os.path.split(os.path.abspath(r"01 今日内容.py")))  #将路径以最后一个切割(路径,文件名)
            # print(os.path.dirname(r"F:s24day171 今日内容.py"))  # 获取路径 ***
            # print(os.path.basename(r"F:s24day171 今日内容.py")) # 获取文件名 **
            # print(os.path.exists(r"F:s24day171 今日内容.py"))  # 判断这个路径是否存在  ***
            # print(os.path.isdir(r"F:s24day17"))     # 判断是不是路径  ***
            # print(os.path.isfile(r"01 今日内容.py"))  # 判断是不是文件  ***
            # print(os.path.isabs(r"F:s24day171 今日内容.py"))     # 判断是不是绝对路径
            # print(os.path.join("D:\\","ttt","bbb"))                # 路径拼接 *****
            # import time
            # print(time.time())
            # print(os.path.getatime(r"F:s24day174 序列化.py"))      # 最后的修改时间
            # print(os.path.getctime(r"F:s24day174 序列化.py"))      # 最后的访问时间
            # print(os.path.getmtime(r"F:s24day174 序列化.py"))      # 最后的访问时间
            # print(os.path.getsize(r"F:s24day09"))                    # 获取当前文件的大小   ***

sys

# sys -- 与python解释器交互的接口

# import sys
# if sys.argv[-1] == "alex":
#     print("dsb")
# else:
#     print("李业dsb")

# print(sys.argv[-1])  # *** 当前文件运行['F:/s24/day17/06 sys.py']


# import sys
# print(sys.exit(1))   #

# import sys
# print(sys.version)  # 获取解释器版本

# import sys
# print(sys.path)     # 添加自定义模块查找路径 *****

# import sys
# print(sys.platform)   # *** 区分操作系统然后进行相关逻辑操作

hash lib

# hashlib 加密
# 加密和校验

# alex:alex123
# alex:23lw23jky321jh4gqyt1234gj8b7t  # 加密后
# {"1234":23lw23jky321jh4gqyt1234gj8b7t}

# md5,sha1,sha256,sha512
# 1.只要明文相同密文就是相同的
# 2.只要明文不相同密文就是不相同的
# 3.不能反逆(不能解密) -- md5中国人破解了

# alex:alex123
# alex:b75bd008d5fecb1f50cf026532e8ae67

# print(len("b75bd008d5fecb1f50cf026532e8ae67"))

# 加密:
#     1.加密的内容
#     2.将要加密的内容转成字节

# import hashlib
# md5 = hashlib.md5()
# md5.update("alex123".encode("utf-8"))
# print(md5.hexdigest())
#
# md5 = hashlib.md5()
# md5.update("alex".encode("utf-8"))
# print(md5.hexdigest())

# md5 = hashlib.md5()
# md5.update("alex123".encode("gbk"))
# print(md5.hexdigest())

# md5 = hashlib.md5()
# md5.update("alex123".encode("shift-jis"))
# print(md5.hexdigest())

# import hashlib
# sha1 = hashlib.sha256()
# sha1.update("alex123".encode("utf-8"))
# print(sha1.hexdigest())

# md5 = hashlib.md5()
# md5.update("alex123".encode("utf-8"))
# print(md5.hexdigest())

# 最常用是的md5,平时加密的时候使用sha1

# 加盐

# 加固定盐
# import hashlib
# md5 = hashlib.md5("常鑫".encode("utf-8"))
# md5.update("alex123".encode("utf-8"))
# print(md5.hexdigest())
#
# md5 = hashlib.md5()
# md5.update("alex123".encode("utf-8"))
# print(md5.hexdigest())


# 动态加盐

# user = input("username:")
# pwd = input("password")
#
# import hashlib
# md5 = hashlib.md5(user.encode("utf-8"))
# md5.update(pwd.encode("utf-8"))
# print(md5.hexdigest())

# md5 = hashlib.md5()
# md5.update(pwd.encode("utf-8"))
# print(md5.hexdigest())

# 767db14ed07b245e24e10785f9d28e29

# f = open(r"F:s24day17python-3.6.6-amd64.exe","rb")
# import hashlib
# md5 = hashlib.md5()
# md5.update(f.read())
# print(md5.hexdigest())

# ss = "baoyuanalextaibai"
# s = "baoyuan"
# s1 = "alex"
# s2 = "taibai"
# import hashlib
# md5 = hashlib.md5()
# md5.update(ss.encode("utf-8"))
# print(md5.hexdigest())
#
#
# md5 = hashlib.md5()
# md5.update(s.encode("utf-8"))
# md5.update(s1.encode("utf-8"))
# md5.update(s2.encode("utf-8"))
# print(md5.hexdigest())

# 节省内存

# f = open(r"F:s24day17python-3.6.6-amd64.exe","rb")
# import hashlib
# md5 = hashlib.md5()
# while True:
#     msg = f.read(1024)
#     if msg:
#         md5.update(msg)
#     else:
#         print(md5.hexdigest())
#         break

collections

# 1.namedtuple: 生成可以使用名字来访问元素内容的tuple
# 2.deque: 双端队列,可以快速的从另外一侧追加和推出对象
# 3.Counter: 计数器,主要用来计数
# 4.OrderedDict: 有序字典
# 5.defaultdict: 带有默认值的字典

from collections import namedtuple,deque
# Point = namedtuple('tu',["a","b","c"]) # 第一个参数是元组的名字,第二参数是元组中元素的[名字,名字]
# p = Point({"keu":(1,2,3,4)}, 20,10)
# print(p)
# tu = (1,2,32,34,4)
# print(tu)

# lst = deque([1,2,3,4,5,6,7])
# lst.append(8)
# lst.appendleft(0)
# lst.pop()
# lst.popleft()
# print(lst[4])

# 队列:先进先出
# 栈:先进后出  --  栈顶

# lst = [1,2,3,4]
# lst.append(5)
# lst.pop(0)

# 5.defaultdict: 带有默认值的字典
# from collections import defaultdict
# dic = defaultdict(list)
# dic["k1"].append(12)
# print(dic)

# li = [11,22,33,44,55,77,88,99,90]
# result = {"key1":[],"key2":[]}
# result = {}
# for row in li:
#     if row > 66:
#         if 'key1' not in result:
#             result['key1'] = []
#         result['key1'].append(row)
#     else:
#         if 'key2' not in result:
#             result['key2'] = []
#         result['key2'].append(row)
# print(result)

# from collections import defaultdict
# dic = defaultdict(set)
# li = [11,22,33,44,55,77,88,99,90]
# for i in li:
#     if i > 66:
#         dic["k1"].add(i)
#     else:
#         dic["k2"].add(i)
# print(dic)

from collections import Counter
# s = "1112233344aaa"
# s = [1,1,2,2,3,3]
# s = (1,2,3,3,4,5,6,7,78)
# print(dict(Counter(s)))  # ***
# 统计元素出现的次数
原文地址:https://www.cnblogs.com/zhangshan33/p/11306229.html