Python的循环与判断语句
1、for循环
1)实现循环打印操作
代码段:
# Author:JiangYiyang
for i in range(0,10):
print("Hello,World",i)
跳出循环:
break 跳出整个循环语句
continue 跳出此轮循环语句
先循环i的值,再循环j的值,当j<5时就会打印i和所以j的值,当j>5时,就会跳出第二个for循环
for i in range(0,3):
print("---------",i)
for j in range(0,10):
if j < 5:
print(j)
else:
break
注意:事实上行首的空白是重要的。它称为缩进。在逻辑行首的空白(空格和制表符)用来决定逻辑行的缩进层次,从而用来决定语句的分组。同一层次的语句必须要有相同的缩进。
先循环i的值,然后再循环j的值,并打印hehe字段,当j大于5的时候,便不会再打印第二轮循环里的hehe
for i in range(0,3):
print("---------",i)
for j in range(0,10):
if j > 5:
continue
print("hehe")
2、if判断语句
通过if判断语句来实现用户名和密码的认证登录
if…else
# Author:JiangYiyang
_username='jyy'
_password='python'
username = input("Please input your name:")
password = input("Please input your password:")
if _password == password and _username == username:
print("Welocme user {name} login.....".format(name=username))
else:
print("Your user ro password input error")
if…elif…else
通过while循环加if判断语句来实现猜年龄的游戏,控制循环的次数为3次。
# Author:JiangYiyang\
aaa = 0
age_of_jyy = 19
while aaa < 2:
guess_age = int(input("Please input age:"))
if age_of_jyy > guess_age:
print("This number is bigger")
elif age_of_jyy == guess_age:
print("yes,you input success")
break
else:
print("This number is samller")
aaa = aaa +1
通过循环来判断用户是否要继续玩
# Author:JiangYiyang
age_of_jyy = 19
count = 0
while count <3:
guess_age = int(input("Please input guess age:"))
if guess_age == age_of_jyy:
print("Input successful")
break
elif guess_age > age_of_jyy:
print("That's a big number.")
else:
print("That's a small number.")
count +=1
if count ==3:
countine_confirm = input("do you want to keep guessing...?")
if countine_confirm != 'n':
count=0