4.读取成绩文件grade.txt，自定义设计数据类型， （1）根据总评=0.7*期末+0.3*平时，计算出所有人成绩 （2）计算出不同教师的学生期末成绩平均分。

在Python中，我们可以使用内置的数据结构如字典（dict）来设计一个自定义的数据类型，例如`Student`，它包含姓名、平时成绩、期末成绩以及对应的教师信息。首先，我们假设grade.txt是一个包含学生信息的文本文件，每一行格式如下：`姓名|平时分数|期末分数|教师ID`。

class Student:
    def __init__(self, name, mid_term_score, final_term_score, teacher):
        self.name = name
        self.mid_term_score = float(mid_term_score)
        self.final_term_score = float(final_term_score)
        self.teacher = teacher

def read_grade_file(filename):
    students = []
    with open(filename, 'r') as file:
        for line in file:
            data = line.strip().split('|')
            name, mid_term, final_term, teacher = data
            students.append(Student(name, mid_term, final_term, teacher))

    return students

def calculate_grades(students):
    total_scores = {}
    
    # 计算每个人的成绩
    for student in students:
        total = 0.7 * student.final_term_score + 0.3 * student.mid_term_score
        if student.teacher not in total_scores:
            total_scores[student.teacher] = [total]
        else:
            total_scores[student.teacher].append(total)

    # 按教师统计期末平均分
    teacher_averages = {teacher: sum(scores) / len(scores) for teacher, scores in total_scores.items()}
    
    return total_scores, teacher_averages

students = read_grade_file('grade.txt')
grades, avg_terminals_by_teacher = calculate_grades(students)

# 打印结果
print("所有人的总成绩:", grades)
print("各教师的期末成绩平均分:", avg_terminals_by_teacher)

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