Python file operations,

Python file operations,

Several file opening modes

Open ('path') # open ('path', 'r + ') by default in read-only mode # open in read/write mode. If there is content, it overwrites the content of the corresponding string from the ground up ('path', 'w') # writes, overwrites the file, and writes again. If there is no file, create an open ('path', 'W + ') # read/write by yourself. The function is the same as that of open ('path', 'A') # Write, Append content at the end of the file, if the file does not exist, create open ('path', 'A' +) # read/write, same as above. The most common open ('path', 'B') # open a binary file open ('path', 'U') # support for all line breaks: Login Registration

#! /Usr/bin/env python # coding: rj8f1_open('user.txt ', 'a +') # single row write # f. write ("wd: 1234") # write multiple rows # names = ["pc: 123 \ n", "panda: 123 \ n"] # f. writelines (names) # interactive registration while True: name = raw_input ('Enter the User name :'). strip () password = raw_input ('enter your password :'). strip () repass = raw_input ('Enter the password again :'). strip () if len (name) = 0: print "the user name cannot be blank. Please enter it again !! "Continue; if len (password) = 0 or password! = Repass: print "Incorrect password" continue; else: print "congratulations, registration successful" break; f. write ("% s: % s" % (name, password) f. close ()

　

#! /Usr/bin/env python # coding: utf-8fo = open ("user.txt") '''num = 1 while True: line = fo. readline () # print repr (line) print "% s --> % s" % (num, line. rstrip ("\ n") num + = 1 if len (line) = 0: break ''' # Read all characters from the file, the dictionary dict1 ={} content = fo. readlines () # Save the lecture file result as a list fo. close () # print contentfor user in content: name = user. rstrip ("\ n "). split (":") [0] # print name dict1 [name] = user. rstrip ("\ n "). split (":") [1] # print dict1 # determine the user's account and password. All are OK and the logon is successful. Otherwise, the error count = 0 while True: count + = 1 if count> 3: print "Sorry, you have entered too many errors and your account is locked. Contact the Administrator "break name = raw_input ('enter User name: '). strip () if name not in dict1: print" the user name does not exist. Please enter it again !! "Continue; password = raw_input ('enter your password: '). strip () if password! = Dict1 [name]: print "Incorrect password input" continue; else: print "congratulations, login successful" break;