#Grading system with try and except to validate
score = input('Enter score: ')
try :
     iscore = float(score)
except :
    iscore = -1
    quit ()
if iscore >= 0.9 :
    print('A')
elif iscore >= 0.8 :
    print('B')
elif iscore >= 0.7 :
    print('C')
elif iscore >= 0.6 :
    print ('D')
elif iscore < 0.6 :
    print ('F')
else :
    print('Invalid score')

ab96bc458cf2dd9e5dae78c9e2f4280b37638be1
<mask token>

<mask token>
try:
    iscore = float(score)
except:
    iscore = -1
    quit()
if iscore >= 0.9:
    print('A')
elif iscore >= 0.8:
    print('B')
elif iscore >= 0.7:
    print('C')
elif iscore >= 0.6:
    print('D')
elif iscore < 0.6:
    print('F')
else:
    print('Invalid score')

score = input('Enter score: ')
try:
    iscore = float(score)
except:
    iscore = -1
    quit()
if iscore >= 0.9:
    print('A')
elif iscore >= 0.8:
    print('B')
elif iscore >= 0.7:
    print('C')
elif iscore >= 0.6:
    print('D')
elif iscore < 0.6:
    print('F')
else:
    print('Invalid score')

#Grading system with try and except to validate
score = input('Enter score: ')
try :
     iscore = float(score)
except :
    iscore = -1
    quit ()
if iscore >= 0.9 :
    print('A')
elif iscore >= 0.8 :
    print('B')
elif iscore >= 0.7 :
    print('C')
elif iscore >= 0.6 :
    print ('D')
elif iscore < 0.6 :
    print ('F')
else :
    print('Invalid score')
