操作符:
算术运算: + - * / % // **
逻辑运算:and or not
身份运算: is not is
不可变数据类型:数字 字符串 字典key
可变数据类型:列表 字典value
优先级:幂运算>正负号>算术运算>比较运算>逻辑运算
流程控制:
if else
guess = input("猜猜老男孩的年龄:")
a = int(guess)
age = 56
if a == age :
print ("you get it")
elif a < age:
print("too small")
else:
print("too big")
while break cuntinue else
count = 3
while count:
username = input("请输入用户名:")
password = input("请输入密码:")
if username == "oldboy" and password == "123":
print("登陆成功!")
break
else:
count -= 1
print("错误!还有",count,"次机会!")
if count == 0:
print("机会用光了,程序退出")