django展示choice字段

class Student(models.Model):

    sex_choices = (
        (0, "女"),
        (1, "男"),
        (2, "保密"),
    )
    name = models.CharField(max_length=32, unique=True, verbose_name="姓名")
    age = models.SmallIntegerField(verbose_name="年龄", default=18)  # 年龄
    sex = models.SmallIntegerField(choices=sex_choices)
    birthday = models.DateField()

    # 一对多的关系:在数据库创建一个关联字段：clas_id
    clas = models.ForeignKey(to="Clas",related_name="student_list",on_delete=models.CASCADE)

    # 一对一的关系：建立关联字段,在数据库中生成关联字段：stu_detail_id
    stu_detail = models.OneToOneField("StudentDetail",related_name="stu",on_delete=models.CASCADE)

    # 多对多的关系：创建第三张关系表
    courses = models.ManyToManyField("Course",related_name="students", db_table="db_student2course")

    class Meta:
        db_table = "db_student"


    def __str__(self):
        return self.name

<thead>
                            <tr>
                                <th>序号</th>
                                <th>姓名</th>
                                <th>年龄</th>
                                <th>性别</th>
                                <th>生日</th>
                                <th>班级</th>
                                <th>选修课程</th>
                            </tr>
                            </thead>
                            <tbody>
                            {% for student in student_list %}
                                <tr>
                                    <td>{{ forloop.counter }}</td>
                                    <td>{{ student.name }}</td>
                                    <td>{{ student.age }}</td>
                                    <td>{{ student.get_sex_display }}</td>
                                    <td>{{ student.birthday|date:'Y-m-d' }}</td>
                                    <td>{{ student.clas.name }}</td>
                                    <td>
                                        {% for course in student.courses.all %}
                                            <button>{{ course.title }}</button>
                                        {% endfor %}
                                    </td>
                                </tr>
                            {% endfor %}
                            </tbody>