six

What it is is:

grader.py

# This program gets a numeric test score from the
# user and displays the corresponding letter grade.

# Variables to represent the grade thresholds
A_score = 90
B_score = 80
C_score = 70
D_score = 60

# Get a test score from the user.
score = int(input('Enter your test score: '))
 
# Determine the grade.
if score >= A_score:
    print('Your grade is A.')
else:
    if score >= B_score:
        print('Your grade is B.')
    else:
        if score >= C_score:
            print('Your grade is C.')
        else:
            if score >= D_score:
                print('Your grade is D.')
            else:
                print('Your grade is F.')