abinoten.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
 
import sys
 
import csv
import argparse
 
ALEVEL_FACTOR = 2
EXAM_FACTOR = 4
POINTS_MULTIPLIER = 40
POINTS_DIVIDER = 48
 
def read_semester_grades(filename):
    """ Reads the semester grades from the given file """
    with open(filename[0], 'r') as grades:
        points = 0        

        reader = csv.reader(grades, delimiter=';')
        for lines, semester in enumerate(reader):
            if len(semester) != 9:
                raise IndexError("One of the semesters doesn't have the "
                                 "expected nine grades.\nLength: {} => {}"
                                 .format(len(semester), semester))
           
            for index, grade in enumerate(semester):
                try:
                    grade = int(grade)
                except ValueError as error:
                    raise ValueError("One of the grades isn't a number. "
                                     "Please correct that.") from error
               
                if not 0 <= grade <= 15:
                    raise ValueError("Your grades should be between 0 and 15.")
               
                if index <= 2:
                    # First three are the a-level courses
                    points += grade * ALEVEL_FACTOR
                else:
                    points += grade
                       
        if lines != 3:
            raise IndexError("The *.csv-file doesn't have the expected "
                             "four lines of semester grades.")
        
        return points
 
def read_exam_grades(grades):
    """ Reads the exam grades from the argument list """
    for grade in grades:
        if not 0 <= int(grade) <= 15:
            raise ValueError("Your grades should be between 0 and 15.")
       
    return sum(map(int, grades))
   
def calculate_average_grade(points):
    """ Calculates the average grade """
    return 17/3 - points/180
 
def main():
    parser = argparse.ArgumentParser(description='Calculates the average grade'
                                                 ' of your A-levels.')
    parser.add_argument('file', metavar='grades.csv',
                        type=str, nargs=1,
                        help='csv file with semester grades')
    parser.add_argument('grades', metavar='grade', type=int, nargs=5,
                        help='five exam grades', choices=range(0,16))
    if len(sys.argv) is 1:
        parser.print_help()
        sys.exit(0)
    args = parser.parse_args()
 
    points_block1 = read_semester_grades(args.file)
    points_block1 *= POINTS_MULTIPLIER
    points_block1 = round(points_block1 / POINTS_DIVIDER, 0)
   
    points_block2 = read_exam_grades(args.grades) * EXAM_FACTOR
    points_sum = points_block1 + points_block2
    average_grade = calculate_average_grade(points_sum)
 
    print(30 * '=')
    print('Points in Block 1: {}'.format(int(points_block1)))
    print('Points in Block 2: {}'.format(points_block2))
    print('Sum (Block1 + Block2): {}'.format(int(points_sum)))
    print(30 * '=')
    print('Average grade: {}'.format(round(average_grade, 2)))
 
if __name__ == "__main__":
    try:
        main()
    except (ValueError, IndexError) as error:
        print(error)
        sys.exit(1)