[PYTHON] Try using django-import-export to add csv data to django

Introduction

In this article, I use the django-import-export library to read the csv file I created by myself into django. django-import-export is a library that allows you to import and export csv files from the management screen. Using this, this time we will create a model such as Book, Publisher, etc., and even read the related (one-to-one or one-to-one) csv file. In addition, I would like to describe the impressions I have used.

Official site: django-import-export

Target person

・ People who want to save the data of their own csv file in the django model ・ People who tried to use django-import-export but didn't work ・ People who know about one-to-one and many-to-one contents of databases

environment

Please install the following packages.

pip install django django-import-export

table of contents

1. Create a project
2. Create app
3. Create csv file
4. Try importing

Project creation

Basic configuration

django-admin startproject config .
python manage.py startapp Book

Since the project and model can be created with the above command, add additional apps and modules in settings.py.

# config/settings.py

INSTALLED_APPS = [
    "import_export",#django-import-Required to use export
    "Book",#App created this time
]

App

This time, we will create three models. Describe as follows in the models of the Book created earlier.

#Book/models.py
from django.db import models
class Publisher(models.Model):
    name = models.CharField("Publisher name",max_length=100,help_text="the publisher")

class Book(models.Model):
    title = models.CharField("title",max_length=100,help_text="本のtitle")
    publisher = models.ForeignKey(Publisher,on_delete=models.CASCADE)

class BookPrice(models.Model):
    book = models.OneToOneField(Book,on_delete=models.CASCADE)
    price = models.IntegerField("List price",help_text="本のList price")

The contents of the model are as follows. ・ Book has many relationships with Publisher ・ BookPrice and Book have a one-to-one relationship

The turn of django-import-export

To import the csv file into these models, set from the management screen. This is where django-import-export comes in. The concrete method is completed by just playing with admin.

#Book/admin.py
from django.contrib import admin
from import_export import resources
from import_export.admin import ImportMixin
from .models import Book,BookPrice,Publisher

class PublisherAdmin(ImportMixin,admin.ModelAdmin):
    class PublisherResource(resources.ModelResource):
        class Meta:
            model = Publisher
            fields = ("id","name",)
    resource_class = PublisherResource

class BookAdmin(ImportMixin,admin.ModelAdmin):
    class BookResource(resources.ModelResource):
        class Meta:
            model = Book
            fields = ("id","title","publisher",)
    resource_class = BookResource


class BookPriceAdmin(ImportMixin,admin.ModelAdmin):
    class BookPriceResource(resources.ModelResource):
        class Meta:
            model = BookPrice
            fields = ("id","book","price",)
    resource_class = BookPriceResource



admin.site.register(Publisher,PublisherAdmin)
admin.site.register(Book,BookAdmin)
admin.site.register(BookPrice,BookPriceAdmin)

** Set the details of the csv file to be imported with Resource. Describe the column to be read in fields. In addition to fields, there are import_id_fields etc., and you can specify the id as a command. In addition, you can change the format that accepts only csv, and whether to import even if there is a change in the data.

csv file creation

From here, create three csv files in Excel. When pointing to other models as shown below, it is possible to link by writing the id number to link. For example, Book's "Kimi no Koe" and "Kimi no Oto" refer to objects from the publisher Nakagawa Bunko. Since the Book of BookPrice has a one-to-one relationship, the id number of BookPrice and book are the same.

Model: Publisher

Model: Book

Model: BookPrice

Try to import

python manage.py createsuperuser #I've been asked a lot, but as it's written
python manage.py runserver

If you go to the django management screen, you'll see the three models you created earlier on the management screen. If you click Publisher in this list, the following screen will be displayed. IMPORT is displayed in the upper right corner of this screen, so import from here. Then, the model you created will be registered. It is also linked with the model, so please check it.

At the end

In this article, I used django-import-export to register the data on the django model. Specifically, we created three models, each of which has a corresponding relationship with the other model, but showed that the data relationship can be maintained by specifying their ids. Next, if I have a chance, I would like to try creating a many-to-many model.