python判断成绩给等级

#!/usr/bin/env python 
score = int(raw_input('Please enter a score:'))
def print_score(g):
        print "your score is %s " % g
if 90 < score <= 100:
        print_score('A')
elif score > 80:
        print_score('B')
elif score > 70:
        print_score('C')
elif score > 60:
        print_score('D')
else:
        print_score('F')