gpa_calc.py

# -*-coding: utf-8-*-

def find_gpa(grade):
    if 100 >= grade >= 90:
        return [grade, 'A+', 4.3]
    elif 89 >= grade >= 85:
        return [grade, 'A', 4.0]
    elif 84 >= grade >= 80:
        return [grade, 'A-', 3.7]
    elif 79 >= grade >= 77:
        return [grade, 'B+', 3.3]
    elif 76 >= grade >= 73:
        return [grade, 'B', 3.0]
    elif 72 >= grade >= 70:
        return [grade, 'B-', 2.7]
    elif 69 >= grade >= 67:
        return [grade, 'C+', 2.3]
    elif 66 >= grade >= 63:
        return [grade, 'C', 2.0]
    elif 62 >= grade >= 60:
        return [grade, 'C-', 1.7]
    elif 59 >= grade >= 50:
        return [grade, 'D', 1.0]
    elif 49 >= grade >= 1:
        return [grade, 'E', 0.0]
    elif grade is 0:
        return [grade, 'X', 0.0]
    else:
        return None


def main():
    #Input Example: 成績1,學分數1 成績2,學分數2 成績3,學分數3 ...
    g = raw_input('Enter your grade: ')
    g = g.strip().split()

    l = []
    for x in g:
        x = x.split(',')
        t = find_gpa(int(x[0]))

        if t is not None:
            t.append(x[1])
            l.append(t)
        else:
            raise BaseException('You have wrong grade.')

    avg = 0.0
    gpa = 0.0
    weights = 0
    for x in l:
        print('{0:4d}  {1:2s} {2:1.1f} {3}'.format(x[0], x[1], x[2], x[3]))
        avg += float(x[0])*int(x[3])
        gpa += float(x[2])*int(x[3])
        weights += int(x[3])

    print('your AVG grade: {0}'.format(avg/weights))
    print('your GPA: {0}'.format(gpa/weights))

if __name__ == "__main__":
    main()