Import from Excel into DB

import.py

import os

from django.contrib import messages
from django.core.exceptions import ValidationError
from django.forms import forms
from django.shortcuts import redirect, render
from xlrd import open_workbook


def validate_import_extension(value):
    """
    Credits to http://stackoverflow.com/a/8826854/2758732
    """

    ext = os.path.splitext(value.name)[1]
    valid_extensions = ['.xls', '.xlsx']
    if ext not in valid_extensions:
        raise ValidationError('Type de fichier non autorisé !')


class ProductImportForm(forms.Form):
    file = forms.FileField(required=True, label='Fichier', validators=[validate_import_extension])


def reset_products(request, factory_pk):
    """
    View
    """
    products = Product.objects.filter(factory=factory_pk)

    context = {
        'products': products
    }

    if request.method == 'POST' or request.method == 'DELETE':
        form = ProductImportForm(request.POST, request.FILES)

        if form.is_valid():
            products.delete()
            with open_workbook(file_contents=request.FILES['file'].read()) as wb:
                for sheet in wb.sheets():
                    number_of_rows = sheet.nrows
                    number_of_columns = sheet.ncols
                    headers = []

                    for row in range(number_of_rows):
                        if row == 0:
                            for col in range(number_of_columns):
                                headers.append(sheet.cell(row, col).value)
                        else:
                            values = {}
                            for col in range(number_of_columns):
                                value = sheet.cell(row, col).value
                                values[headers[col]] = value
                            product = Product(**values)
                            product.factory_id = factory_pk
                            product.save()

            messages.success(request, 'Produits importés')
            return redirect('codes:factory_home', factory_pk=factory_pk)
        else:
            messages.error(request, 'Formulaire invalide')

    else:
        form = ProductImportForm()

    context['form'] = form

    return render(request, 'codes/product/import.html', context)