如何以编程方式获取Django模型字段的max_length？

pip install django

django-admin startproject myproject
cd myproject

python manage.py startapp myapp

from django.db import models

class MyModel(models.Model):
    my_field = models.CharField(max_length=100)

from django.http import HttpResponse
from .models import MyModel

def get_max_length(request):
    field = MyModel._meta.get_field('my_field')
    max_length = field.max_length
    return HttpResponse(f"The max_length of the my_field field in MyModel is {max_length}.")

from django.urls import path
from . import views

urlpatterns = [
    path('get_max_length/', views.get_max_length, name='get_max_length'),
]

from django.contrib import admin
from django.urls import path, include

urlpatterns = [
    path('admin/', admin.site.urls),
    path('myapp/', include('myapp.urls')),
]

python manage.py runserver

http://localhost:8000/myapp/get_max_length/

The max_length of the my_field field in MyModel is 100.