CODEWITHSUNDEEP
pythonpython-3.x
AnEnigma
AnEnigma

Reputation: 1

How can I fix my code for calculating Body Mass Index for Python?

I'm using Python 3.5.1, and I need to make a BMI calculator using the formula 703 * weight/height^2, after I input my height and weight, I get "TypeError: can't multiply sequence by non-int of type 'str'"

And I'm honestly not sure how to fix it. This is my code.

def calculateBMI():
    weight = input("Please enter weight in pounds: ")
    height = input("Please enter height in inches: ")

    return weight * ((703.0) / (height * height))

bmi = calculateBMI()

print ("""Your BMI is""", str(bmi))

if bmi < 18.5:
    print("You are underweight.")
elif bmi > 25:
    print("You are overweight.")
else:
    print ("You are of optimal weight.")

Upvotes: 0

Views: 1954

Answers (2)

lochsh
lochsh

Reputation: 376

Before I help out, I just wanted to point out that the code you have pasted has no indentation. Python is indentation-sensitive -- did you just paste it wrong, or is this how your code actually looks? :)

Now, there are probably two problems here:

  1. Python version

When I try running this code, it is able to take input from the command line fine. I am using Python 2.7.8. The raw_input method has been renamed to input in Python 3. So, if you are using Python 3, you should change the raw_input to input.

If you are on Linux, you can find out your Python version on the console like this:

    $ python --version
  1. Floats and strings

When you take input from the command line, using input or raw_input, it is saved as a string, as shown here in the docs

https://docs.python.org/3/library/functions.html#input

If you want to multiply the two values together, you have to convert them to float, like this:

weight = float(input("Please enter weight: "))
height = float(input("Please enter height: "))

I hope this solves your problems :)

Upvotes: 0

Robᵩ
Robᵩ

Reputation: 168636

There are three errors in your program:

  • Since you are using Python3, you need to use input(), not raw_input() to read the user's weight and height.

  • You need to convert the user's data to a numeric type using int() or float().

  • Your indentation is incorrect.

Here is a program that works:

def calculateBMI():
    weight = int(input("Please enter weight: "))
    height = int(input("Please enter height: "))

    return weight * ((703.0) / (height * height))
bmi = calculateBMI()

print ("""Your BMI is""", str(bmi))

if bmi < 18.5:
    print("You are underweight.")
elif bmi > 25:
    print("You are overweight.")
else:
    print ("You are of optimal weight.")

Upvotes: 4

Related Questions