def main():
 
    letter(A) = ["100", "99", "98", "97",
              "96", "95", "94", "93", "92", "91", "90"]
    letter2(B) = ["89", "88", "87",
              "86", "85", "84", "83", "82", "81", "80"]
    #and so on... but afeter this i have no idea how to make computer look at the
    #right list and print the corresponding grade...
 
 
 
 
    score = input("Enter quiz score: ")
 
 
                             #over here... how do i make computer look at letter
 
    print "Letter grade is", letter[score-1] + "."
 
main()

get the numeric score
look up the score in a list   # < This is the part you're trying to solve.
print result

if score < 60:
    grade = 'F'

if score >= 90:
    grade = 'A'

if score >= 80 and score <= 89:
    grade = 'B'

if score < 60:
     grade="F"
elif score < 70:
     grade="D"
elif score < 80:
     grade="C"
elif score < 90:
     grade="B"
elif score < 101:
     grade="A"
else:
     print score, "is bogus"