if块内的print语句始终不执行？Python代码问题求助

我编写了一段体重维持计算器的Python代码，运行时无论输入活动水平为0、1还是2，if块内的caloriesUsedCurrently始终无法打印，且无报错信息。代码如下：

print("Welcome to the weight maintenance calculator!")
startWeight = float(input("Input your start weight, in kilograms: "))
height = float(input("Enter your height in centimetres: "))
sex = input("Enter your sex (M/F): ")
age = float(input("Enter your age: "))
dailyActivity = input("Rank your activity level, from 0-5: ")

if ((sex == "M") or (sex == "m")):
    startWeightBmr = int((10 * startWeight) + (6.25 * height) - (5 * age) + 5)
    if (dailyActivity == 0):
        caloriesUsedCurrently = startWeightBmr + 300
        print(caloriesUsedCurrently)
    if (dailyActivity == 1):
        caloriesUsedCurrently = startWeightBmr + 350
        print(caloriesUsedCurrently)
    if (dailyActivity == 2):
        caloriesUsedCurrently = startWeightBmr + 400
        print(caloriesUsedCurrently)

问题核心：input()函数获取的输入默认是字符串类型，而你在判断条件里把它和整数0/1/2做比较，两者类型不匹配，条件永远不成立，所以代码块不会执行。

有两种直接的修复方式：

方式一：将输入转为整数类型 #

修改dailyActivity的输入语句，把输入转成整数：

dailyActivity = int(input("Rank your activity level, from 0-5: "))

方式二：将判断条件中的数字改为字符串 #

保持输入为字符串，把判断里的整数换成对应的字符串：

if (dailyActivity == "0"):
    caloriesUsedCurrently = startWeightBmr + 300
    print(caloriesUsedCurrently)
if (dailyActivity == "1"):
    caloriesUsedCurrently = startWeightBmr + 350
    print(caloriesUsedCurrently)
if (dailyActivity == "2"):
    caloriesUsedCurrently = startWeightBmr + 400
    print(caloriesUsedCurrently)

额外优化建议 #

1. 用elif代替多个独立if，避免不必要的条件判断：

if dailyActivity == 0:
    caloriesUsedCurrently = startWeightBmr + 300
elif dailyActivity == 1:
    caloriesUsedCurrently = startWeightBmr + 350
elif dailyActivity == 2:
    caloriesUsedCurrently = startWeightBmr + 400
print(caloriesUsedCurrently)

2. 补充女性（F/f）的BMR计算逻辑，当前代码只处理了男性情况；
3. 增加对活动等级超出0-5范围的异常提示，避免无输出的情况。

内容的提问来源于stack exchange，提问作者frosted flakes