# The body of loops can contain any statements
# A loop (outer loop) can contain another loop (inner loop).


for i in range(5):
    print("i =", i)
    for j in range(3):
        print("   j =", j)
print("done nested loop example (#1)")


for i in range(5):
    print("i =", i)
    for j in range(100):
        if input("    Stop inner loop? ") == "yes":
            break
        print("        j =", j)
print("done nested loop example, using break (#2)")


# Write a function that takes a list of grades
# Each item (in the list of grades) contains grades for each course
# the student took.
# The function returns a list of averages of the courses.
# Example:
#    list_of_grades = [[80, 90], [90, 89, 97], [75, 90, 100], [70, 75, 90, 85]]
# the function returns averages = [85.0, 92.0, 83.33, 80.0]

def compute_averages(lst):
    """
    The function takes a list of grades and
    returns a new list in which each item is
    the average of the grades for each course
    """

    # get a list of grades of each course (i.e., each inner list)
    # compute its average as sum the grades divided by number of grades

    average = []

    for course_grades in lst:
        total = 0         # keep track of total grades of each course
        for grade in course_grades:
            total += grade
        course_avg = total / len(course_grades)

        average.append(course_avg)

    return average

list_of_grades = [[80, 90], [90, 89, 97], [75, 90, 100], [70, 75, 90, 85]]
print(compute_averages(list_of_grades))