9. review: my output right, but get an error


#1

Hi, this code works, but I get an error message!!!!! The error message gives me this:

Oops, try again.
It looks like not all grades were printed! Make sure you are printing ech one on their own line.

THIS IS MY CODE:
grades = [100, 100, 90, 40, 80, 100, 85, 70, 90, 65, 90, 85, 50.5]

def print_grades(grades):
for grade in grades:
print grade

def grades_sum(grades):
total = 0
for grade in grades:
total += grade
return total

def grades_average(grades):
sum_of_grades = grades_sum(grades)
average = sum_of_grades / float(len(grades))
return average

def grades_variance(scores):
average = grades_average(scores)
variance = 0
numerator = 0
for score in scores:
numerator += (average - score) ** 2
variance = numerator / float(len(scores))
return variance

def grades_std_deviation(variance):
return float(variance) ** 0.5

print grades
print grades_sum(grades)
print grades_average(grades)
print grades_variance(grades)
print grades_std_deviation(grades_variance(grades))

THIS IS MY OUTPUT:

[100, 100, 90, 40, 80, 100, 85, 70, 90, 65, 90, 85, 50.5]
1045.5
80.4230769231
334.071005917
18.2776094147
None

can you please help me understand what is going on?


#2

Hi this line

print grades

You created a function print_grades() so you should use it for printing all the grades