Django Module for Country Data

continent.py

from django.db import models
from django.utils.translation import pgettext_lazy

from utility.models import BaseModel, BaseModelAdmin


class Continent(BaseModel):
    name = models.CharField(max_length=255,
                            primary_key=True,
                            verbose_name=pgettext_lazy('Continent',
                                                       'name'))
    description = models.TextField(blank=True,
                                   verbose_name=pgettext_lazy('Continent',
                                                              'description'))

    class Meta:
        # Define the database table
        db_table = 'locations_continents'
        ordering = ['name']
        verbose_name = pgettext_lazy('Continent', 'Continent')
        verbose_name_plural = pgettext_lazy('Continent', 'Continents')

    def __str__(self):
        return self.name


class ContinentAdmin(BaseModelAdmin):
    pass

country.py

import csv
import io

from django.db import models
from django.contrib import messages
from django.shortcuts import render, redirect
from django.urls import path
from django.utils.translation import pgettext_lazy

from .continent import Continent
from .language import Language

from utility.forms import CSVImportForm
from utility.models import BaseModel, BaseModelAdmin


class Country(BaseModel):
    name = models.CharField(max_length=255,
                            primary_key=True,
                            verbose_name=pgettext_lazy('Country',
                                                       'name'))
    description = models.TextField(blank=True,
                                   verbose_name=pgettext_lazy('Country',
                                                              'description'))
    capital = models.CharField(max_length=255,
                               blank=True,
                               verbose_name=pgettext_lazy('Country',
                                                          'capital'))
    continent = models.ForeignKey('Continent',
                                  on_delete=models.PROTECT,
                                  verbose_name=pgettext_lazy('Country',
                                                             'continent'))
    languages = models.ManyToManyField('Language',
                                       verbose_name=pgettext_lazy('Country',
                                                                  'language'))

    class Meta:
        # Define the database table
        db_table = 'locations_countries'
        ordering = ['name']
        verbose_name = pgettext_lazy('Country', 'Country')
        verbose_name_plural = pgettext_lazy('Country', 'Countries')

    def __str__(self):
        return self.name


class CountryAdmin(BaseModelAdmin):
    change_list_template = 'utility/import_csv/change_list.html'

    def get_urls(self):
        urls = [
            path('import/', self.import_csv),
        ] + super().get_urls()
        return urls

    def import_csv(self, request):
        def append_error(type_name, item):
            """Append an error message to the messages list"""
            error_message = pgettext_lazy(
                'Country',
                'Unexpected {TYPE} "{ITEM}"'.format(TYPE=type_name,
                                                    ITEM=item))
            if error_message not in error_messages:
                error_messages.append(error_message)
                self.message_user(request, error_message, messages.ERROR)

        if request.method == "POST":
            # Preload continents
            continents = {}
            for item in Continent.objects.all():
                continents[item.name] = item
            # Preload languages
            languages = {}
            for item in Language.objects.all():
                languages[item.name] = item
            # Load CSV file content
            csv_file = io.TextIOWrapper(
                request.FILES['csv_file'].file,
                encoding=request.POST['encoding'])
            reader = csv.DictReader(
                csv_file,
                delimiter=request.POST['delimiter'])
            # Load data from CSV
            error_messages = []
            countries = []
            country_language = {}
            for row in reader:
                if row['CONTINENT'] not in continents:
                    append_error('continent', row['CONTINENT'])
                elif row['LANGUAGE'] not in languages:
                    append_error('language', row['LANGUAGE'])
                else:
                    # If no error create a new Country object
                    country = Country(name=row['NAME'],
                                      description=row['DESCRIPTION'],
                                      capital=row['CAPITAL'],
                                      continent=continents[row['CONTINENT']])
                    country_language[row['NAME']] = row['LANGUAGE']
                    countries.append(country)
            # Save data only if there were not errors
            if not error_messages:
                Country.objects.bulk_create(countries)
                self.message_user(request, pgettext_lazy(
                    'Country',
                    'Your CSV file has been imported'))
                # Add language in each country
                for country in countries:
                    country.languages.set(
                        (languages[country_language[country.name]], ))
            return redirect('..')
        return render(request,
                      'utility/import_csv/form.html',
                      {'form': CSVImportForm()})

language.py

from django.db import models
from django.utils.translation import pgettext_lazy

from utility.models import BaseModel, BaseModelAdmin


class Language(BaseModel):
    name = models.CharField(max_length=255,
                            primary_key=True,
                            verbose_name=pgettext_lazy('Language',
                                                       'name'))
    description = models.TextField(blank=True,
                                   verbose_name=pgettext_lazy('Language',
                                                              'description'))

    class Meta:
        # Define the database table
        db_table = 'locations_languages'
        ordering = ['name']
        verbose_name = pgettext_lazy('Language', 'Language')
        verbose_name_plural = pgettext_lazy('Language', 'Languages')

    def __str__(self):
        return self.name


class LanguageAdmin(BaseModelAdmin):
    pass