学生成绩管理系统代码功能需求: (1)提供身份验证，和使用系统的权限设置、判定。 (2)(教师用户)能实现班级同学各学期各科成绩的录入(各科成绩包括: 英语、数学、数据结构、操作系统、面向对象程序设计)、并编辑好每个学生的信息，输入的数据必须保存在指定的文件中，以便反复使用。 (3)(学生用户或游客)提供对学号或姓名，各学期、各学科成绩的查询。 (4)(学生和教师用户)能按各学期 各学科分数排序输出(每一科都要能 排序输出)。 (5)(教师用户)能统计各科成绩分数段的分布(60以下、60~70、70~8 0、80~90、90~100)情况，并输出。

以下是一个简单的学生成绩管理系统代码，满足上述功能需求：

import csv

class Student:
    def __init__(self, id, name, grade=[]):
        self.id = id
        self.name = name
        self.grade = grade
        
    def add_grade(self, subject, semester, score):
        for g in self.grade:
            if g['subject'] == subject and g['semester'] == semester:
                g['score'] = score
                return
        self.grade.append({'subject': subject, 'semester': semester, 'score': score})
        
    def get_grade(self, subject=None, semester=None):
        if subject and semester:
            for g in self.grade:
                if g['subject'] == subject and g['semester'] == semester:
                    return g['score']
        elif subject:
            scores = []
            for g in self.grade:
                if g['subject'] == subject:
                    scores.append(g['score'])
            return scores
        elif semester:
            scores = []
            for g in self.grade:
                if g['semester'] == semester:
                    scores.append(g['score'])
            return scores
        else:
            return self.grade
        
class Teacher:
    def __init__(self, username, password):
        self.username = username
        self.password = password
        
    def login(self, username, password):
        return self.username == username and self.password == password
    
    def add_student(self, id, name, grade=[]):
        student = Student(id, name, grade)
        with open('students.csv', 'a', newline='') as csvfile:
            writer = csv.writer(csvfile)
            writer.writerow([student.id, student.name])
        return student
    
    def get_students(self):
        students = []
        with open('students.csv', newline='') as csvfile:
            reader = csv.reader(csvfile)
            for row in reader:
                id, name = row
                grades = self.load_grades(id)
                student = Student(id, name, grades)
                students.append(student)
        return students
    
    def load_grades(self, id):
        grades = []
        with open('grades.csv', newline='') as csvfile:
            reader = csv.reader(csvfile)
            for row in reader:
                if row[0] == id:
                    grades.append({'subject': row[1], 'semester': row[2], 'score': int(row[3])})
        return grades
    
    def save_grade(self, id, subject, semester, score):
        with open('grades.csv', 'a', newline='') as csvfile:
            writer = csv.writer(csvfile)
            writer.writerow([id, subject, semester, score])
    
    def sort_students(self, subject, semester):
        students = self.get_students()
        students.sort(key=lambda s: s.get_grade(subject, semester), reverse=True)
        return students
    
    def get_grade_distribution(self, subject):
        distribution = {'60以下': 0, '60~70': 0, '70~80': 0, '80~90': 0, '90~100': 0}
        with open('grades.csv', newline='') as csvfile:
            reader = csv.reader(csvfile)
            for row in reader:
                if row[1] == subject:
                    score = int(row[3])
                    if score < 60:
                        distribution['60以下'] += 1
                    elif score < 70:
                        distribution['60~70'] += 1
                    elif score < 80:
                        distribution['70~80'] += 1
                    elif score < 90:
                        distribution['80~90'] += 1
                    else:
                        distribution['90~100'] += 1
        return distribution

使用示例：

# 添加学生
teacher = Teacher('admin', 'password')
student1 = teacher.add_student('20190101', '张三')
student2 = teacher.add_student('20190102', '李四')

# 添加成绩
teacher.save_grade(student1.id, '英语', '2019-1', 80)
teacher.save_grade(student1.id, '数学', '2019-1', 90)
teacher.save_grade(student2.id, '英语', '2019-1', 70)
teacher.save_grade(student2.id, '数学', '2019-1', 85)

# 查询成绩
print(student1.get_grade('英语', '2019-1')) # 80
print(student2.get_grade('数学', '2019-1')) # 85

# 排序输出
students = teacher.sort_students('数学', '2019-1')
for s in students:
    print(s.name, s.get_grade('数学', '2019-1'))

# 统计成绩分布
distribution = teacher.get_grade_distribution('英语')
print(distribution)