如何在Django中创建自定义命令?

from django.contrib.auth import get_user_model
User = get_user_model()
# retrieve all usersusers = User.objects.all()
# loop through all usersfor user in users:    print(f'user is {user.get_full_name()} and their username is {user.get_username()}')

django.core.exceptions.ImproperlyConfigured: Requested setting AUTH_USER_MODEL, but settings are not configured. You must either define the environment variable DJANGO_SETTINGS_MODULE or call settings.configure() before accessing settings

import os
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'projectname.settings')
import djangodjango.setup()
from django.contrib.auth import get_user_model
User = get_user_model()
users = User.objects.all()
for user in users:    print(f'user is {user.get_full_name()} and their username is {user.get_username()}')

from django.db import modelsfrom django.contrib.auth import get_user_model
User = get_user_model()
# Create your models here.class CommonInfo(models.Model):    created_at = models.DateTimeField(auto_now_add=True)    updated_at = models.DateTimeField(auto_now=True)
class Meta:        abstract = True        ordering = ('-created_at',)
# blog post categoryclass Category(CommonInfo):    name = models.CharField(max_length=255)
def __str__(self):return self.name
# blog post instanceclass Post(CommonInfo):    title = models.CharField(max_length=255)    category = models.ForeignKey(Category,related_name='posts',on_delete=models.PROTECT)    author = models.ForeignKey(User,related_name='posts',on_delete=models.PROTECT)    content = models.TextField()    published = models.BooleanField(default=False)
def __str__(self):return f'{self.title} by {self.author.get_full_name()}'

import osos.environ.setdefault('DJANGO_SETTINGS_MODULE', 'commands.settings')
import djangodjango.setup()
from django.contrib.auth import get_user_modelfrom posts.models import Category, Post
User = get_user_model()
def select_category():# retrieve categories. (You can create some examples from the django admin)    categories = Category.objects.all().order_by('created_at')    print('Please select a category for your post: ')for category in categories:        print(f'{category.id}: {category}')    category_id = input()    category = Category.objects.get(id=category_id)return category

def select_author():# retrieve all users    users = User.objects.all()    print('Please select an author for your post: ')for user in users:        print(f'{user.id}: {user}')    user_id = input()    user = User.objects.get(id=user_id)return user


def create_post():    title = input("Title of your post: ")    content = input("Long post content: ")    category = select_category()    author = select_author()    Post(**locals()).save()    print('Post created successfully!')
if __name__ == "__main__":    create_post()

from django.core.management.base import BaseCommand, CommandErrorfrom posts.models import Category, Post
class Command(BaseCommand):    help = 'Marks the specified blog post as published.'
# allows for command line argsdef add_arguments(self, parser):        parser.add_argument('post_id', type=int)
def handle(self, *args, **options):try:            post = Post.objects.get(id=options['post_id'])except Post.DoesNotExist:raise CommandError(f'Post with id {options["post_id"]} does not exist')if post.published:            self.stdout.write(self.style.ERROR(f'Post: {post.title} was already published'))else:            post.published = True            post.save()            self.stdout.write(self.style.SUCCESS(f'Post: {post.title} successfully published'))

from django.core.management.base import BaseCommand, CommandErrorfrom posts.models import Category, Post
class Command(BaseCommand):    help = 'Edits the specified blog post.'
def add_arguments(self, parser):        parser.add_argument('post_id', type=int)
# optional arguments        parser.add_argument('-t', '--title',type=str, help='Indicate new name of the blog post.')        parser.add_argument('-c', '--content',type=str, help='Indicate new blog post content.')
def handle(self, *args, **options):        title = options['title']        content = options['content']try:            post = Post.objects.get(id=options['post_id'])except Post.DoesNotExist:raise CommandError(f'Post with id {options["post_id"]} does not exist')
if title or content:if title:                old_title = post.title                post.title = title                post.save()                self.stdout.write(self.style.SUCCESS(f'Post: {old_title} has been update with a new title, {post.title}'))if content:                post.content = content                post.save()                self.stdout.write(self.style.SUCCESS('Post: has been update with new text content.'))else:            self.stdout.write(self.style.NOTICE('Post content remains the same as no arguments were given.'))