比较运算符

逻辑运算符

## 比较运算符
a, b, c = 10, 3, 7
print(a >= b) #True
print(a > b) #True
print(a < b) #True
print(a <= b) #True
print(a == b) # False
print(a != b) # False
# 逻辑运算符  与 或 非
print((a > c) and (a > b)) # True    &&
print((a > c) and (a < b)) # False

print((a > c) or (a > b)) # True   ||
print((a < c) or (a > b)) # True
print((a < c) or (a < b)) # False

print(not (a < c)) # True   !

程序执行结构

• 顺序结构
• 分支结构
• 循环结构

分支结构(条件语句)

if语句

age = int(input("请输入您的年龄"))
# TypeError: '>=' not supported between instances of 'str' and 'int'

if age >= 18 and age <=60:
    print("恭喜你成年了, 可以去网吧了")
    print("恭喜你成年了, 还不赶快行动")
elif age > 60 and age <=150:
    print("退休啦")
elif age >=0  and age <=18:
    print("你还是个宝宝")
else:
    print("输入数据有误")

作业

BMI计算器
计算公式为：BMI=体重÷身高^2。（体重单位：千克；身高单位：米。）

猜拳游戏

# 猜拳游戏
from random import randint
computer = randint(1, 3)  # [1, 3] 左闭右闭
# print(computer)
player = int(input("请出拳: ⽯头（1）剪⼑（2）布（3）"))
if (player==1 and computer==2)or(player==2 and computer==3)or(player==3 and computer==1):
    print("玩家胜利啦")
elif player==computer:
    print("平局")
else:
    print("你真菜, 我赢了")

循环

# while
# while 条件:
#     循环体
i = 1
mySum = 0
while i <= 100:
    print(i, end="\t")
    mySum += i
    i+=1
print()
print(mySum)
# break 跳出本层循环
# 累加和达到大于1000停止
i = 1
mySum = 0
while i <= 100:
    if mySum > 1000:
        break
    mySum += i
    i+=1
print()
print("mySum = ", mySum)

# continue 结束本次循环执行下一次循环
# 1~100之间所有奇数的累加和
i = 1
mySum = 0
while i <= 100:
    if i%2 == 0:
        i+=1
        continue
    mySum += i
    i+=1
print()
print("mySum = ", mySum)

for 循环

# for循环
# for 临时变量 in 可迭对象:
#     循环体
# range(起始, 终止, 步长)  左闭右开区间 步长不能为小数
# for i in range(10):
# for i in range(1, 101):
# for i in range(1, 101, 10):
mySum = 0
for i in range(1, 101):
    mySum +=i
print("mySum = ", mySum)
# # break 跳出本层循环
# # 累加和达到大于1000停止
mySum = 0
for i in range(1, 101):
    if mySum > 1000:
        break
    mySum +=i
print("mySum = ", mySum)
# # continue 结束本次循环执行下一次循环
# # 1~100之间所有奇数的累加和

mySum = 0
for i in range(1, 101):
    if i %2 == 0:
        continue
    mySum +=i
print("mySum = ", mySum)