按相同数组值计算多维数组的值

def calculate_average_scores(arr):
    result = []
    subjects = set()
    
    # 遍历整个数组，找出所有科目
    for student in arr:
        for subject, score in student:
            subjects.add(subject)
    
    # 对每个科目进行计算
    for subject in subjects:
        scores = []
        count = 0
        
        # 找出所有相同科目的成绩数据
        for student in arr:
            for subj, score in student:
                if subj == subject:
                    scores.append(score)
                    count += 1
        
        # 计算平均分数
        average_score = sum(scores) / count
        
        # 添加科目和平均分数到结果数组中
        result.append([subject, average_score])
    
    return result