python module

module sys module (and interpreter related modules)

Module import module:

        import sys

        sys.path.append("D:");

        for i in sys.path:

              print(i)

 

The os module of the module (the module related to the system)

import os
str1='D:'
str2='home'
str3='index'
t=os.path.join(str1,str2,str3)
print(t)

os.stat('path/filename')
os.path.dirname(path)
os.path.exists(path)
os.path.join(path1,path2,path3)

 Very important

ask.com

biying.com

stackoverflow.com

 Secure MD5 encryption

import hashlib 

ha=hashlib.md5(bytes('123',encoding='utf-8')) 

ha.update(bytes('123',encoding='utf-8')) 
print(ha.hexdigest()) 


#The following is an example of MD5 actual application login

import hashlib
def register(user,pwd):
    with open('haha','w',encoding='utf-8') as f:
        f.write(user+'|'+md5(pwd))
        f.close()
def login(name,pwd):
    with open('haha','r',encoding='utf-8') as f:
        for line in f:
            c,d=line.strip().split('|')
            if c==name and d==md5(pwd):
                return True
            else:
                return False
def md5(pwd):
    ha=hashlib.md5(bytes('guozhendong',encoding='utf-8'))
    ha.update(bytes(pwd,encoding='utf-8'))
    return ha.hexdigest()
i=input("1.登录；2.注册")
if i=='2':     pwd=input('Password:')
    name=input('Username:')

    register(name,pwd) 
if i=='1': 
    name = input('username:') 
    pwd = input('password:') 
    t=login(name,pwd) 
    if t==True: 
        print(" Login successful") 
    else: 
        print("Login failed") 



#end