(TypeError: unsupported operand type(s) for : 'int' and 'list') calculating the-CodePudding

I'm trying to calculate the average score. but there seems to be some problem with my code. I'm not sure what to do but it says in the introduction: f) Create a new list called avg_scores that is the list of average extra credit test scores of Marla, Ashford, and Sam. • Use the data from the updated all_scores to calculate the averages. You do NOT need nested for loops for this step. • Use a single for loop to access each inner list, then calculate the average of the inner list. Append that average to the avg_scores list. • Display avg_scores.

# a
m_list = []
print("Please enter Marla's scores one by one.")
for i in range(3):
    m_test = int(input("Enter a score: "))
    m_list.append(m_test)
print("Marla's scores: ", m_list)

# b
a_list = []
print("Please enter Ashford's scores one by one.")
for i in range(3):
    a_test = int(input("Enter a score: "))
    a_list.append(a_test)
print("Ashford's scores: ", a_list)

# c
s_list = []
print("Please enter Sam's scores one by one.")
for i in range(3):
    s_test = int(input("Enter a score: "))
    s_list.append(s_test)
print("Sam's scores: ", s_list)

# d
all_scores = []
for i in (m_list, a_list, s_list):
    all_scores.append(i)
print("All scores: ", all_scores)

# e
for i in range(len(all_scores)):
    for p in range(len(all_scores[i])):
        all_scores[i][p] = all_scores[i][p]   2
print("All scores after extra point:", all_scores)

# f
sum_scores = sum(all_scores)
len_scores = len(all_scores)
avg_scores = sum_scores/len_scores
print("Average scores: ", avg_scores)

CodePudding user response：

all_scores is a 2-D list, so you need to take each list and add its sum to sum_scores using a for loop:

avg_scores = []
for scores in all_scores:
    avg_scores.append(sum(scores) / len(scores))

Alternatively, if you want something more concise, you can do:

avg_scores = list(score / 3 for score in map(sum, all_scores))

(I've only included this approach for completeness; most developers would not reasonably expect someone just starting out to be familiar with this syntax.)

CodePudding user response：

To compute the average for each student, you need to take sum(scores) / len(scores) for each scores list in all_scores, i.e.:

avg_scores = [sum(scores) / len(scores) for scores in all_scores]

Note that you can take advantage of for loops to get the scores for each student without having to copy and paste the same code for each one individually:

all_scores = []
for name in ("Marla", "Ashford", "Sam"):
    print(f"Please enter {name}'s scores one by one.")
    all_scores.append([int(input("Enter a score: "))for _ in range(3)])

print("All scores:", all_scores)

all_scores = [[i   2 for i in scores] for scores in all_scores]
print("All scores after extra point:", all_scores)

avg_scores = [sum(scores) / len(scores) for scores in all_scores]
print("Average scores:", avg_scores)

Please enter Marla's scores one by one.
Enter a score: 5
Enter a score: 5
Enter a score: 4
Please enter Ashford's scores one by one.
Enter a score: 3
Enter a score: 5
Enter a score: 4
Please enter Sam's scores one by one.
Enter a score: 5
Enter a score: 5
Enter a score: 5
All scores: [[5, 5, 4], [3, 5, 4], [5, 5, 5]]
All scores after extra point: [[7, 7, 6], [5, 7, 6], [7, 7, 7]]
Average scores: [6.666666666666667, 6, 7]