P2PU Python Course: ex.4.7

# -*- coding: utf-8 -*-
"""
Created on Tue Mar 26 13:07:49 2013
Exercise 4.7
@author: casa
"""
def computegrade(s):
    if s > 1 :
        g = 'None'
    elif s > 0.9 :
        g = 'A'
    elif s > 0.8 :
        g = 'B'
    elif s > 0.7 :
        g = 'C'
    elif s > 0.6 :
        g = 'D'
    else :
        g = 'F'
    return g

while (True):
    score = raw_input("Enter score: ")
    if score == "done" :
        print("Bye bye")
        break
    try:
        print score
        score = float(score)
        grade = computegrade(score)
    except:
        print("Bad score")
        continue
    print("Grade: "), grade
exit()