使用Python检查变量是否介于两个值之间

Question

我在Python 3中计算一个人的BMI,需要检查BMI是否介于两个值之间.

这是我的代码:

def metricBMI():

    text = str('placeholder')

    #Get height and weight values 
    height = float(input('Please enter your height in meters: '))
    weight = float(input('Please enter your weight in kilograms: '))

    #Square the height value
    heightSquared = (height * height)

    #Calculate BMI
    bmi = weight / heightSquared

    #Print BMI value
    print ('Your BMI value is ' + str(bmi))

    if bmi < 18:
        text = 'Underweight'

    elif 24 >= bmi and bmi >= 18:
        text = 'Ideal'

    elif 29 >= bmi and bmi >= 25:
        text = 'Overweight'

    elif 39 >= bmi and bmi >= 30:
        text = 'Obese'

    elif bmi > 40:
        text = 'Extremely Obese'

    print ('This is: ' + text)

这将输出Underweight非常好,但像Ideal这样的其他人不会定义文本.

输出:

Calulate BMI, BMR or Harris Benedict Equation (HBE) or exit? bmi
Do you work in metric (M) or imperial (I)m
Please enter your height in meters: 1.8
Please enter your weight in kilograms: 80
Your BMI value is 24.691358024691358
This is: placeholder

我猜测我检查变量的方式有问题,但我看不到它.

谢谢,

可靠的人

Answer 1

您的BMI不属于您的任何条件(超过24且低于25,并且您的情况不包括在内).

事实上,你可以像这样简化你的条件:

if bmi < 18:
    text = 'Underweight'

elif bmi <= 24: # we already know that bmi is >=18 
    text = 'Ideal'

elif bmi <= 29:
    text = 'Overweight'

elif bmi <= 39:
    text = 'Obese'

else:
    text = 'Extremely Obese'