Weighted average

Question

the following code receives from user some grades on coursers that he took in previous semester and their weights. when user is done he will type "done" instead the grade. I need to complete a code that compute weighted average and store it in variable res rounded to hundredths.

weighted average = sum(grade*points)/sum(points)

here is what I tried so far:

    grade = input("enter your grade: ")
    points = input("enter the points: ")
    #innitialise the variables before while loop:
    
sum_grade = 0
    sum_points = 0

    #write a while loop that terminates when the user enters "done" to grade variable

    #calculate the grade to variable res in this format XX.XX

    while grade != "done":
        sum_grade += int(grade)
        sum_points += int(points)
        grade = input("enter your grade: ")
        points = input("enter the points: ")
        continue
        else:
        break
        
    res = sum_grade*sum_points / sum_points

    res ="%.2f"%float

Thank you in advanced :-)

Answer 1

You have the right pieces. You just need to put them in the right order.

Try this code:

sum_grade = 0
sum_points = 0
while True:
    grade = input("enter your grade: ")
    if grade == "done": break  # done
    points = int(input("enter the points: "))
    grade = int(grade)
    sum_grade += grade * points
    sum_points += points
    
res = sum_grade / sum_points

res ="%.2f"%res

print(res)

Output

enter your grade: 10
enter the points: 10
enter your grade: 50
enter the points: 1
enter your grade: done
13.64

Answer 2

You can either use Numpy as following :

import numpy as np

np.average(sum_grade, axis=1, weights=sum_points)

or by modfying your code as follow :

sum_grade += int(grade*points)

and

res = sum_grade / sum_points