Open a file in read mode and add functions (Python)

Question

I wrote a python program to create an output file with the filename scores.txt, asked the user to enter test scores (-10 to end) of a class, and wrote them to the file. The program then should open this file, read scores from the file to display letter grade for each score. This will be done by creating a function called 'display_letter' and will classify each score as following: If 90> then A, if 80> then B, etc.

Below is my code to create scores.txt, how can I open this file with the described function above?

def main():
    outfile=open('scores.txt','w')
    score=int(input('Enter the scores (-10 to stop):'))
    
    while score !=-1:
        outfile.write(str(score)+ '
')
        score=int(input('Enter the scores (-10 to stop):'))
    
    outfile.close()
    print('Data is written')
main()

question from:https://stackoverflow.com/questions/65896261/open-a-file-in-read-mode-and-add-functions-python

Answer 1

To read, you open the file you have written in a similar way as before, except you use 'r' instead of 'w'. Then you you iterate through each line of your newly-read data, strip the newline characters, and evaluate the number written on each line.

data = open('scores.txt', 'r')
for line in data:
    grade = line.rstrip("
")
    if int(grade) >= 90:
        print(grade, "A")
    elif int(grade) >= 80:
        print(grade, "B")
    elif int(grade) >= 70:
        print(grade, "C")
    elif int(grade) >= 60:
        print(grade, "D")
    else:
        print(grade, "F")