不明白为何结果返回的是空列表

#类的定义example.py

class Student(object):
   """学生类"""
   def __init__(self, s_name, s_number):
       self.s_name = s_name
       self.s_number = s_number
       self.s_course = []

   @property
   def course_detail(self):
       return self.s_course

   def add_course(self, cour_info):
       self.s_course.append(cour_info)

   def __str__(self):
       return 'name: {p1}, s_number: {p2}'.format(p1 = self.s_name, p2 = self.s_number)


class Teacher(object):
   """教师类"""
   def __init__(self, t_number, t_name, t_phone):
       self.t_number = t_number
       self.t_name = t_name
       self.t_phone = t_phone

   def __str__(self):
       return 't_number: {p1}, t_name: {p2}'.format(p1 = self.t_number, p2 = self.t_name)


class Course(object):
   """课程类"""
   def __init__(self, c_number, c_name, c_teacher = None):
       self.c_number = c_number
       self.c_name = c_name
       self.c_teacher = c_teacher

   def binding(self, teacher):
       if isinstance(teacher, Teacher):
           self.c_teacher = teacher
           dict = {}
           return dict.update(课程名称 = self.c_name, 教师名称 = self.c_teacher)
       else:
           return None

#完成业务逻辑file_exe.py

from example import Student, Teacher, Course


def introduction(str):
   print('********************{0}********************'.format(str))

def prepare_course():
   course_dict = {"01": "网络爬虫", "02": "数据分析", "03": "人工智能", "04": "机器学习", "05": "云计算", "06": "大数据", "07": "图像识别", "08": "Web开发"}
   course_list = []
   for key, value in course_dict:
       course_mooc = Course(key, value)
       course_list.append(course_mooc)
   return course_list

def creat_teacher():
   all_teacher_info = [["T1", "张亮", "13301122001"], ["T2", "王朋", "13301122002"], ["T3", "李旭", "13301122003"], ["T4", "黄国发", "13301122004"], ["T5", "周勤", "13301122005"], ["T6", "谢富顺", "13301122006"], ["T7", "贾教师", "13301122007"], ["T8", "杨教师", "13301122008"]]
   teacher_list = []
   for i in range(0, len(all_teacher_info)):
       teacher_info = all_teacher_info[i]
       teacher_instance = Teacher(teacher_info[0], teacher_info[1], teacher_info[2])
       teacher_list.append(teacher_instance)
   return teacher_list

def course_to_teacher():
   course_to_teacher_list = []
   ls_course = prepare_course()
   ls_teacher = creat_teacher()
   ls_teacher.reverse()
   for i in range(0, len(ls_course)):
       course_data = ls_course[i]
       course_to_teacher_data = course_data.binding(ls_teacher[i])
       course_to_teacher_list.append(course_to_teacher_data)
   return course_to_teacher_list

def creat_student():
   ls_student = ["小亮", "小明", "李红", "小丽", "Jone", "小彤", "小K", "慕慕"]
   ls_s_number = []
   for i in range(1000, 1008):
       ls_s_number.append(i)
   ls_student.reverse()
   number_to_student_list = []
   for p in range(0, len(ls_s_number)):
       number_to_student_data = Student(ls_student[p], ls_s_number[p])
       number_to_student_list.append(number_to_student_data)
   return number_to_student_list

if __name__ == '__main__':
   course_to_teacher()
   creat_student()
   introduction('慕课学院(1)班学生信息')
   for i in creat_student():
       print(i)
   introduction('慕课学院(1)班选课结果')
   for p in range(0, len(course_to_teacher())):
       creat_student()[p].add_course(course_to_teacher()[p])
        #print(creat_student()[p].course_detail)
   for x in creat_student():
         result = 'name: {p1}, Selected: {p2}'.format(p1 = x.s_name, p2 = x.course_detail)
         print(result)