Cfrgtkky

I'm practicing previous python exam question for an upcoming exam but my code is screwy.

1. The task is to make a text file with a list of weights in grams (done).




2. Prompts user for file name, reads the weights, adds them in a list and calculates the total weight.

Herein lies the problem:

try:



   file = input('Enter file name:')



   f = open('weights.txt', 'r')



   sum=0



   for line in f:



      sum = sum+(int(line.strip()))/1000



      print('The textbook weight in kg:', sum)



except:



   print('File cannot be opened')

The output the programme shows is:

"The textbook weight in kg: 0.5

The textbook weight in kg: 0.65

The textbook weight in kg: 1.35

The textbook weight in kg: 1.6500000000000001

The textbook weight in kg: 1.9000000000000001"

But the output i need is:

1.9 only,without the previous lines.

As I'm still a beginner, I know very little about the correct code. So any help will be appreciated

Your problem is with your indentation. You should print your result after the whole for loop is executed, i.e.

try:

    file = input('Enter file name:')

    f = open('weights.txt', 'r')

    sum=0   

    for line in f:

        sum = sum+(int(line.strip()))/1000

    print('The textbook weight in kg:', sum)

except:

    print('File cannot be opened')

Also for the floating point inaccuracy thing, you could format your print like this:

print('The textbook weight in kg:{:.2f}'.format(sum))

# The textbook weight in kg:1.90