如何在django模型中从一个字段添加多个输入

from django.db import models

class Author(models.Model):
    name = models.CharField(max_length=100)

class Book(models.Model):
    title = models.CharField(max_length=100)
    authors = models.ManyToManyField(Author)

python manage.py makemigrations
python manage.py migrate

from django.shortcuts import render
from .models import Book

def add_book(request):
    if request.method == 'POST':
        title = request.POST['title']
        author_ids = request.POST.getlist('authors')
        book = Book.objects.create(title=title)
        book.authors.set(author_ids)
        return render(request, 'success.html')
    else:
        authors = Author.objects.all()
        return render(request, 'add_book.html', {'authors': authors})

<form method="post" action="{% url 'add_book' %}">
  {% csrf_token %}
  <label for="title">Title:</label>
  <input type="text" name="title" id="title">
  <label for="authors">Authors:</label>
  <select name="authors" id="authors" multiple>
    {% for author in authors %}
      <option value="{{ author.id }}">{{ author.name }}</option>
    {% endfor %}
  </select>
  <input type="submit" value="Add Book">
</form>