[DRF #1] Django REST framework

DRF

ㅘ

일단 모르겠지만,
하나하나 부시는거지 뭐

Django REST framework 튜토리얼 #1

1. 설치

#가상환경 세팅하고

pip install requests
pip install django
pip install djangorestframework

2. models.py 작성 (튜토리얼 그대로)

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']
        
        
# 마이그레이션마이그레이트하구요

python manage.py makemigrations snippets
python manage.py migrate

3. serializers.py (또 그대로)

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
        

여기까지 일단 뭔지 모르겠고 작성을 한 뒤에,
이제 shell로!!!

Serializer

장고 모델 데이터를 JSON 타입으로 변환하여 API 통신을 함

# 모듈을 불러오고,

>>> from snippets.models 	  import Snippet
>>> from snippets.serializers 	  import SnippetSerializer
>>> from rest_framework.renderers import JSONRenderer
>>> from rest_framework.parsers   import JSONParser

>>> snippet = Snippet(code='foo = "bar"\n')
>>> snippet.save()
>>> snippet = Snippet(code='print("hello, world")\n')
>>> snippet.save()

# 인스턴스로 데이터에 접근
>>> serializer = SnippetSerializer(snippet)
>>> serializer.data
{'id': 8, 'title': '', 'code': 'print("hello, world")\n', 'linenos': False, 'language': 'python', 'style': 'friendly'}
# serializer는 딕셔너리 타입

>>> Snippet.objects.values()
<QuerySet [{'id': 8, 'created': datetime.datetime(2021, 12, 27, 17, 23, 33, 914895, tzinfo=datetime.timezone.utc), 'title': '', 'code': 'print("hello, world")\n', 'linenos': False, 'language': 'python', 'style': 'friendly'}]>

# model instance를 Python native datatypes로 변환함

>>> print(type(snippet))
<class 'snippets.models.Snippet'>
>>> print(type(serializer.data))
<class 'rest_framework.utils.serializer_helpers.ReturnDict'>

# data를 JSON화 함
>>> content = JSONRenderer().render(serializer.data)
>>> content
b'{"id":8,"title":"","code":"print(\\"hello, world\\")\\n","linenos":false,"language":"python","style":"friendly"}'

Deserializer

JSON을 다시 Python 딕셔너리로

>>> import io
>>> stream = io.BytesIO(content)
>>> data = JSONParser().parse(stream)
>>> data
{'id': 8, 'title': '', 'code': 'print("hello, world")\n', 'linenos': False, 'language': 'python', 'style': 'friendly'}

>>> type(content)
<class 'bytes'>

>>> type(stream)
<class '_io.BytesIO'>

>>> type(data)
<class 'dict'>

딕셔너리를 객체로 저장

  
>>> serializer = SnippetSerializer(data=data)

# 데이터 유효성 검사
>>> serializer.is_valid()
True

>>> serializer.validated_data
OrderedDict([('title', ''), ('code', 'print("hello, world")'), ('linenos', False), ('language', 'python'), ('style', 'friendly')])

# serializer.validated_data가 뭔가 싶어 찍어보면
  
>>> a = serializer.validated_data
>>> type(a)
<class 'collections.OrderedDict'>

>>> serializer.save()
<Snippet: Snippet object (9)>

>>> Snippet.objects.all()
<QuerySet [<Snippet: Snippet object (1)>, <Snippet: Snippet object (2)>, <Snippet: Snippet object (3)>, <Snippet: Snippet object (4)>, <Snippet: Snippet object (5)>, <Snippet: Snippet object (6)>, <Snippet: Snippet object (7)>, <Snippet: Snippet object (8)>, <Snippet: Snippet object (9)>]>

#모델 인스턴스 대신에 쿼리셋으로 many=True를 사용하여 serialize 할 수 있음
>>> serializer = SnippetSerializer(Snippet.objects.all(), many=True)
>>> serializer.data
[OrderedDict([('id', 1), ('title', ''), ('code', 'foo = "bar"\n'), ('linenos', False), ('language', 'python'), ('style', 'friendly')]), OrderedDict([('id', 2), ('title', ''), ('code', 'print(123)'), ('linenos', False), ('language', 'python'), ('style', 'friendly')]), OrderedDict([('id', 3), ('title', ''), ('code', 'print(456)'), ('linenos', False), ('language', 'python'), ('style', 'friendly')]), OrderedDict([('id', 4), ('title', ''), ('code', 'print(456)'), ('linenos', False), ('language', 'python'), ('style', 'friendly')]), OrderedDict([('id', 5), ('title', ''), ('code', 'print(456)'), ('linenos', False), ('language', 'python'), ('style', 'friendly')]), OrderedDict([('id', 6), ('title', ''), ('code', 'print(456)'), ('linenos', False), ('language', 'python'), ('style', 'friendly')]), OrderedDict([('id', 7), ('title', ''), ('code', 'foo = "bar"\n'), ('linenos', False), ('language', 'python'), ('style', 'friendly')]), OrderedDict([('id', 8), ('title', ''), ('code', 'print("hello, world")\n'), ('linenos', False), ('language', 'python'), ('style', 'friendly')]), OrderedDict([('id', 9), ('title', ''), ('code', 'print("hello, world")'), ('linenos', False), ('language', 'python'), ('style', 'friendly')])]

일단 뭐 이렇게 된다는 건데,,,