python基础(二)-循环

占位符:%s %d %f %r
分别代表:str, int num, float num, raw str


位运算,将字符转换成二进制后进行运算

&: 与
|: 或
^: 异或
~: 按位取反
>>: 右移，移动1位等于除以2，2位等于除以4
<<: 左移，移动1位等于乘以2，2位等于乘以4

a b & | ^
0 0 0 0 0
0 1 0 1 1
1 0 0 1 1
1 1 1 1 0

msg = '%s %d %f %r' %('sd\nf', 123, 123.123, '\n\t')
print(msg)


# 二进制运算
# 128 64 32 16 8 4 2 1

a = 20 # 20 = 0001 0100
b = 13 # 13 = 0000 1101
c = a & b
d = a | b
e = a ^ b
f = ~a
g = a >> 2 # 0001 0100 -> 0101 0000
h = a << 2 # 0001 0100 -> 0000 0101
# 0001 0100 = 20
# 1110 1011 = 235
# 255 - 235  = -20

print(c,d,e,f,g,h)

# for循环，尝试10次猜年龄，第三次的时候选择是否要继续玩

AGE = 20


for i in range(10):

    print("you have %d times left" %(10-i))
    guess_age = int(input("Please guess jeff's age: "))


    if guess_age == AGE:
        print("You are right!")
        break
    elif guess_age < AGE:
        print("guess smaller")
    else:
        print("guess lager")
    if i == 2:
        print("too many tries")
        Yn = input("Do you want to coutine?(Yes/No)")
        if Yn == 'Yes' or Yn == 'Y' or Yn == 'y':
            pass
        elif Yn == 'No' or Yn == 'N' or Yn == 'n':
            break