djangorestframework 实践（一）： quicklystart

Setting up a new environment

Before we do anything else we'll create a new virtual environment, using venv. This will make sure our package configuration is kept nicely isolated from any other projects we're working on.

python3 -m venv env
source env/bin/activate

Now that we're inside a virtual environment, we can install our package requirements.

pip install django
pip install djangorestframework
pip install pygments  # We'll be using this for the code highlighting

Getting started

Okay, we're ready to get coding. To get started, let's create a new project to work with.

cd ~
django-admin startproject tutorial
cd tutorial

Once that's done we can create an app that we'll use to create a simple Web API.

python manage.py startapp snippets

We'll need to add our new snippets app and the rest_framework app to INSTALLED_APPS. Let's edit the tutorial/settings.py file:

INSTALLED_APPS = [
    ...
    'rest_framework',
    'snippets.apps.SnippetsConfig',
]

Creating a model to work with

For the purposes of this tutorial we're going to start by creating a simple Snippet model that is used to store code snippets. Go ahead and edit the snippets/models.py file. Note: Good programming practices include comments. Although you will find them in our repository version of this tutorial code, we have omitted them here to focus on the code itself.

from django.db import models
from pygments.lexers import get_all_lexers
from pygments.styles import get_all_styles

LEXERS = [item for item in get_all_lexers() if item[1]]
LANGUAGE_CHOICES = sorted([(item[1][0], item[0]) for item in LEXERS])
STYLE_CHOICES = sorted([(item, item) for item in get_all_styles()])


class Snippet(models.Model):
    created = models.DateTimeField(auto_now_add=True)
    title = models.CharField(max_length=100, blank=True, default='')
    code = models.TextField()
    linenos = models.BooleanField(default=False)
    language = models.CharField(choices=LANGUAGE_CHOICES, default='python', max_length=100)
    style = models.CharField(choices=STYLE_CHOICES, default='friendly', max_length=100)

    class Meta:
        ordering = ['created']

Meta

模型的元数据

We'll also need to create an initial migration for our snippet model, and sync the database for the first time.

python manage.py makemigrations snippets
python manage.py migrate

Creating a Serializer class

The first thing we need to get started on our Web API is to provide a way of serializing and deserializing the snippet instances into representations such as json. We can do this by declaring serializers that work very similar to Django's forms. Create a file in the snippets directory named serializers.py and add the following.

from rest_framework import serializers
from snippets.models import Snippet, LANGUAGE_CHOICES, STYLE_CHOICES


class SnippetSerializer(serializers.Serializer):
    id = serializers.IntegerField(read_only=True)
    title = serializers.CharField(required=False, allow_blank=True, max_length=100)
    code = serializers.CharField(style={'base_template': 'textarea.html'})
    linenos = serializers.BooleanField(required=False)
    language = serializers.ChoiceField(choices=LANGUAGE_CHOICES, default='python')
    style = serializers.ChoiceField(choices=STYLE_CHOICES, default='friendly')

    def create(self, validated_data):
        """
        Create and return a new `Snippet` instance, given the validated data.
        """
        return Snippet.objects.create(**validated_data)

    def update(self, instance, validated_data):
        """
        Update and return an existing `Snippet` instance, given the validated data.
        """
        instance.title = validated_data.get('title', instance.title)
        instance.code = validated_data.get('code', instance.code)
        instance.linenos = validated_data.get('linenos', instance.linenos)
        instance.language = validated_data.get('language', instance.language)
        instance.style = validated_data.get('style', instance.style)
        instance.save()
        return instance

替换

Let's look at refactoring our serializer using the ModelSerializer class. Open the file snippets/serializers.py again, and replace the SnippetSerializer class with the following.

class SnippetSerializer(serializers.ModelSerializer):
    class Meta:
        model = Snippet
        fields = ['id', 'title', 'code', 'linenos', 'language', 'style']

运行

python manage.py runserver 0:80

转载链接：
https://www.django-rest-framework.org/tutorial/1-serialization/#getting-started