python 循环语句教学_python『学习之路01』循环语句任性玩

python 循环语句;

一 循环的基本用法及格式:.

while 循环:　 --- >>　当...条件时成立时执行语句体,

python  --- >> 格式:

while( 判断条件 ):

语句体；

java：----  >> 格式:

while( 判断条件 ){

语句体；}

例：

i =0

while (i < 3):

print "good"     // ---->>当i小于3时,输出good

java: ------ >>

int i =0

while (i < 3):

System.out.println("good")     // ---->>当i小于3时,输出good

死循环:

while  True:

print("我是死循环");

java ------ >>

while(true){

System.out.println("我是死循环");

}

for 循环:

for  i in index:

print i     // ------ >> 循环输出index的各字母:

for i in range(0,10):

print i   // ------- >>顺序输出0-9

'''

range中可携带三个参数:例 range(0,10,2)

for i in range(0,10,2):

print i     // ----- >>  隔行打数, 每两个数打印一次:

'''

二 循环案例:

限定用户登录,每次登录失败提示剩余登录次数,登录成功调用猜数字游戏,  三次登录失败后提示账号锁定.三次猜数字机会，

猜测成功和三次三次猜测错误都给与提示,是否想再玩一次?， 是则重新开始猜数字游戏, 否则退出游戏.程序结束:

python 版

用户登录:

#!/usr/bin/env python

# -*- coding: utf-8 -*-

# @Time : 2017/11/14 13:06

# @Author : mixiu26

import guess as ges

# 定义已有用户名：

username = "admin"

password = "admin"

count = 0

while(count<3):# 用户输入账号密码:

name = input("name: ")

pwd = input("pwd: ")

# 对已有用户名进行校验:

if((username == name) and (password == pwd)):

count += 1

print("yes! you got it!")

Guess= ges.GuessAge()

Guess.guess()

break;

elif (2-count == 0):

# 输入失败的过程中需要再次进行判断, 是否已经到达第三次, 当到达第三次时要告知用户账户已锁定:

print("用户名或密码输入有误: ")

print("对不起, 您的账户已被锁定,请与管理员联系: ")

break;

else:

print("用户名或者密码输入有误: " + "您还有" +str((2 - count))+ "次机会")

count += 1

for 循环 guess age：

#!/usr/bin/env python

# -*- coding: utf-8 -*-

# @Time : 2017/11/14 13:06

# @Author : mixiu26

age_of_girl = 52

count = 0

chance = 'y'

# for 循环格式: ---- >> for i in range(循环次数) --->> i就代表我们循环的变量次数

for num in range(0,99999999999999999999):

guess_age = int(input("guess age: "))

if count <= 2:

if guess_age == age_of_girl:

print("yes, you got it!")

count += 1

elif guess_age >= age_of_girl:

if count == 2:

print("sorry, your guess age were too large and sorry, you have no chance. ")

else:

print("sorry, your guess age were too large , sorry,please try once again:")

count += 1

elif guess_age <= age_of_girl:

if count == 2:

print("sorry, your guess age were too small and: sorry, you have no chance. ")

else:

print("sorry, your guess age were too small , sorry,please try once again:")

count += 1

if ((guess_age == age_of_girl) or (count == 3 )):

print("do you try once again? ")

choice = input("your Choice: ")

if(chance == choice):

count=0

else:

print("Thank you! ")

break;

while  --- >> 格式版

#!/usr/bin/env python

# -*- coding: utf-8 -*-

# @Time : 2017/11/14 13:06

# @Author : mixiu26

age_of_girl= 52

count = 0

chance = 'y'

while count <= 3:

guess_age = int(input("guess age: "))

if count <= 2:

if guess_age == age_of_girl:

print("yes, you got it!")

count += 1

elif guess_age >= age_of_girl:

if count == 2:

print("sorry, your guess age were too large and sorry, you have no chance. ")

else:

print("sorry, your guess age were too large , sorry,please try once again:")

count += 1

elif guess_age <= age_of_girl:

if count == 2:

print("sorry, your guess age were too small and: sorry, you have no chance. ")

else:

print("sorry, your guess age were too small , sorry,please try once again:")

count += 1

if ((guess_age == age_of_girl) or (count == 3)):

print("do you try once again? ")

choice = input("your Choice: ")

if (chance == choice):

count = 0

else:

print("Thank you! ")

break;

1. java版代码实现:

import GuessGame.GuessNumber;

import java.util.Scanner;

/**

* Created by mixiu26 on 2017/11/14.

*

* 模拟登录, 限定三次机会,每次输入都提示下次剩余机会数:

* 登录成功后不立即退出,要求调用猜数字游戏:

*

*/

public class StringTest2 {

public static void main(String[] args) {

//定义已有用户名/ 密码:

String username = "admin";

String password = "admin";

//给定用户三次机会：

for (int x = 0; x < 3; x++) {

//创建键盘录入对象:

Scanner sc = new Scanner(System.in);

System.out.println("请输入用户名: ");

//键盘接收已输入用户名及密码:

String name = sc.nextLine();

System.out.println("请输入账户密码:");

String pwd = sc.nextLine();

//接收输入参数后将账户数据与原数据进行比对:

if (username.equals(name) && password.equals(pwd)) {

System.out.println("登录成功: ");

// break;

//调用猜数字游戏:

GuessNumber.star();

break;

} else {

//输入失败的过程中需要再次进行判断,是否已经到达第三次,当到达第三次时,要告知用户账户已锁定:

if (2 - x == 0) {

System.out.println("用户名或者密码输入有误: ");

System.out.println("对不起, 您的账户已被锁定,请与管理员联系: ");

} else {

//判断条件为用户名和密码都和原始数据相同时,才登录成功,所以else走的就是不相同的情况,不需要再加入条件判断：

System.out.println("用户名或者密码输入有误: " + "您还有" + (2 - x) + "次机会");

}

}

}

}

}

guess 部分:

package GuessGame;

import java.util.Scanner;

/**

* Created by mixiu26 on 2017/11/14.

*/

public class GuessNumber {

private GuessNumber(){} // 私有限定,禁止构造调用

public static void star() {

System.out.println("进入猜数字小游戏");

int count = 0;

//产生一个随机数:

int number = (int)(Math.random() * 100) +1;

//键盘录入数据,与随机数进行比较： ---- >> 要求限定三次机会,三次机会后进行询问是否还要继续玩游戏:

Scanner sc = new Scanner(System.in);

String chance = "y";

for(; ;) {

System.out.println("请输入您猜测的数据: ");

int guessNumber = sc.nextInt();

//比较两个数据是否相等：

if(count<3) {

if (guessNumber == number) {

System.out.println("yes, you got it! ");

count += 1;

} else if (guessNumber > number) {

if (2 - count== 0) {

System.out.println("sorry, your guess age were too large and sorry, you have no chance.");

} else {

System.out.println("sorry, your guess age were too large , sorry,please try once again:");

}

count += 1;

} else {

if (2 - count == 0) {

System.out.println("sorry, your guess age were too small and sorry, you have no chance.");

} else {

System.out.println("sorry, your guess age were too small , sorry,please try once again:");

}

count += 1;

}

}

if ((guessNumber == number) || (count == 3)) {

System.out.println("do you try once again? ");

Scanner sc2 = new Scanner(System.in);

String choice = sc2.nextLine();

if(choice.equals(chance)){

count = 0;

}else {

System.out.println("Thank you!");

break;

}

}

}

}

}