range类使用异常求助：基于体重身高的区间判断逻辑实现疑问

Hey there! Let's sort out this BMI check logic for you. First off, let's clear up why range isn't working for your case: the range class in Python is designed to generate sequences of integers (like range(1, 5) gives you 1,2,3,4). But your BMI calculation will almost certainly be a floating-point number (e.g., 22.7, 18.9), so range can't properly check if a float falls within a continuous numerical interval.

Instead, we'll use simple comparison operators to handle the ranges, which is way more straightforward for this kind of check. Here's the full, working code with explanations:

Step 1: Calculate BMI Correctly #

First, you need to convert height from centimeters to meters (since BMI uses meters for height). Then compute the BMI value:

# Get user inputs
weight = float(input('What is your weight (kg)? '))
height_cm = float(input('What is your height (cm)? '))

# Convert height to meters and calculate BMI
height_m = height_cm / 100
bmi = weight / (height_m ** 2)

Step 2: Add the Range Check Logic #

Now use if-elif-else to evaluate the BMI against your desired ranges:

# Check BMI ranges and output the corresponding message
if bmi < 19:
    print("you are skinny as rail")
elif 19 <= bmi <= 25:
    print("you are fit as a butcher's dog")
else:  # BMI >25
    print("you are as plum as a partridge")

Putting It All Together #

Here's the complete script:

weight = float(input('What is your weight (kg)? '))
height_cm = float(input('What is your height (cm)? '))

height_m = height_cm / 100
bmi = weight / (height_m ** 2)

if bmi < 19:
    print("you are skinny as rail")
elif 19 <= bmi <= 25:
    print("you are fit as a butcher's dog")
else:
    print("you are as plum as a partridge")

Why This Works Better Than range #

• range is meant for iterating over integer sequences, not checking if a float falls within a continuous numerical range.
• Direct comparisons (<, <=, >=, >) are precise for floating-point values and make your logic easy to read and maintain.

内容的提问来源于stack exchange，提问作者Shahzad Khan