import getpass

 #标准库里要加密密码需要导包getpass.但是getpass在pycharm中不好用,需要在命令窗口中输入才管用.

 _username = "abc"

 _password = "abc123"

 username = input("username:")

 # password = getpass.getpass("password:")

 password = input("password:")

 if _username==username and _password==password:

     print("Welcome user {name} login...".format(name=username))

 else:

     print("invalid username or password")

 age_of_oldboy = 56

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

 if guess_age==age_of_oldboy:

     print("yes, you got it.")

 elif guess_age>age_of_oldboy:

     print("think smaller")

 else:

     print("think bigger")

 age_of_oldboy = 56

 count=0

 while True:

     if count==3:

         break

     # print("count:",count)

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

     if guess_age==age_of_oldboy:

         print("yes, you got it.")

         break

     elif guess_age>age_of_oldboy:

         print("think smaller")

     else:

         print("think bigger")

     count=count+1  #count+=1

 if count==3:

     print("you have tried too many times! Fuck off!")

 # 优化后的代码

 while count<3:

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

     if guess_age==age_of_oldboy:

         print("yes, you got it.")

         break

     elif guess_age>age_of_oldboy:

         print("think smaller")

     else:

         print("think bigger")

     count=count+1  #count+=1

 else:

     print("you have tried too many times! Fuck off!")

 '''

 while循环实现

 age_of_oldboy = 56

 count=0

 while True:

     if count==3:

         break

     # print("count:",count)

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

     if guess_age==age_of_oldboy:

         print("yes, you got it.")

         break

     elif guess_age>age_of_oldboy:

         print("think smaller")

     else:

         print("think bigger")

     count=count+1  #count+=1

 if count==3:

     print("you have tried too many times! Fuck off!")

 # 优化后的代码

 while count<3:

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

     if guess_age==age_of_oldboy:

         print("yes, you got it.")

         break

     elif guess_age>age_of_oldboy:

         print("think smaller")

     else:

         print("think bigger")

     count=count+1  #count+=1

 else:

     print("you have tried too many times! Fuck off!")

 '''

 '''

 for i in range(10):   #range10其实是从0到9.

     print("loop", i)

 '''

 # for循环来实现

 age_of_oldboy = 56

 for i in range(3):

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

     if guess_age == age_of_oldboy:

         print("yes, you got it")

         break

     elif guess_age > age_of_oldboy:

         print("think smaller")

     else:

         print("think bigger")

 else:

     print("you have tried too many times.. fuck off!")

 # 0到9的数字,隔一个打印一个到控制台

 for i in range(0,10,2):   #括号中的2是步长,不写的话默认是1.若想隔两个打印一uqw,则步长设置为3即可.即for i in range(0,10,3)

     print("loop", i)

 # 每错三次不直接跳出,而是问玩家是否要继续

 age_of_oldboy = 56

 count=0

 while True:

     if count==3:

         break

     # print("count:",count)

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

     if guess_age==age_of_oldboy:

         print("yes, you got it.")

         break

     elif guess_age>age_of_oldboy:

         print("think smaller")

     else:

         print("think bigger")

     count=count+1  #count+=1

     if count==3:

         continue_confirm = input('do you want to continue?')

         if continue_confirm !='n':

             count=0

 else:

     print("you have tried too many times! Fuck off!")

 # continue的用法: 跳出本次循环,继续下一次循环

 for i in range(0,10):

     if i<5:

         print("loop", i)

     else:

         continue  #跳出本次循环,继续下一次循环

     print("hehe...")

 #break:结束当前循环

 for i in range(10):

     print("-----------------",i)

     for j in range(10):

         print(j)

         if j>5:

             break