Little white Python road day1 expression if ... else, while loop, for loop

Expression If ... else

First, user login verification

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# 提示输入用户名和密码 # 验证用户名和密码#     如果错误，则输出用户名或密码错误#     如果成功，则输出 欢迎，XXX!#!/usr/bin/env python# -*- coding: encoding -*-  _username = ' Qian '_password = ' zxc123 'username = input ("username:")password = input ("Password:")if _username = = Username and _password = = Password:print ("Welcome user {name} login ...". Format (name=username))Else:print ("Invalid username or password!")

Second, guess the age game

Set your age in the program, and then start the program to let the user guess, after the user input, according to his input prompts the user to enter the correct, if the error, the hint is guessed big or small,

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#!/usr/bin/ Env python #-*-coding:utf-8-*- my_age = +   guess_age = Int (input ("Guess Age:")) if guess_age = my_age: print ("Yes, you got it.") elif guess_age > My_age: print ("think smaller ...") else: print ("Think bigger!")  

Second, while loop

There's a cycle called a dead loop.

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count =0while True:    print("死循环",count)    count +=1

The above guess age with while loop to achieve: guess only 3 times

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#!/usr/bin/env python# -*- coding: utf-8 -*-Count = 0 My_Age =While count < 3:guess_age = Int (input ("Guess Age:"))if Guess_age = = My_age:print ("Yes, you got it.") Breakelif guess_age > My_age:print ("Think smaller ...")Else:print ("Think bigger!")Count +=1Else:print ("You have tried too many times. Fuck off ")

Third, expression for loop

The simplest loop 5 times

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#_*_coding:utf-8_*___author__ =‘Many Qian‘  for i inrange(5):    print("loop:", i )

Output:

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loop: 0loop: 1loop: 2loop: 3loop: 4

Requirements one: or the above program, but encountered less than 5 cycle times will not go, jump directly into the next cycle

1234	for  i  in   Range ( 10 ):      if  i< 5 :          continue   #不往下走了, go directly to the next loop      print ( "loop:"

Requirements Two: or the above program, but encountered more than 5 cycles will not go, direct exit

1234	for  i  in   Range ( 10 ):      if  I> 5 :          break   #不往下走了, jump right out of the loop      print ( "loop:"

Use the For loop you learned above to guess age:

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#!/usr/bin/env python# -*- coding: utf-8 -*-My_Age =For I in range (3):guess_age = Int (input ("Guess Age:"))if Guess_age = = My_age:print ("Yes, you got it.") Breakelif guess_age > My_age:print ("Think smaller ...")Else:print ("Think bigger!")Else:print ("You have tried too many times. Fuck off ")

Little white Python road day1 expression if ... else, while loop, for loop