First of all, look at the model.

from django.db import models

    class Book(models.Model):

        title = models.CharField(max_length=100)

        description = models.TextField(blank=True)

It's a simple model with title and description. Now lets create the functions.

CSV Format:

CSV is the most common import and export format for databases.It's a textual format. Python comes with a built-in CSV library called csv. 

import csv

    from django.http import HttpResponse

    from app_name.models import Book

    def generate_book_csv(request):
        books = Book.objects.all()


        # Create the HttpResponse object with CSV header.This tells browsers that 
        # the document is a CSV file.
        response = HttpResponse(content_type='text/csv')

        # The response also has additional Content-Disposition header, which contains 
        # the name of the CSV file.
        response['Content-Disposition'] = 'attachment; filename=books.csv'

        # The csv.writer function takes file-like object as argument i.e.,HttpResponse object
        writer = csv.writer(response)

        # For each row in your CSV file, call writer.writerow function by passing 
        # a list or tuple to it.
        writer.writerow(['ID', 'Title', 'Description'])

        for book in books:
            writer.writerow([book.id, book.title, book.description])
        return response

Finally return the response object. 

Excel Format:

Excel is the main spreadsheet format which holds data in worksheets, charts etc. We are going to use xlwt library to create a spreadsheet.

First you need to install xlwt library using the command - pip install xlwt

import xlwt
    from django.http import HttpResponse
    from app_name.models import Book

    def generate_book_excel(request):
        books = Book.objects.all()

        # Create the HttpResponse object with Excel header.This tells browsers that 
        # the document is a Excel file.
        response = HttpResponse(content_type='application/ms-excel')

        # The response also has additional Content-Disposition header, which contains 
        # the name of the Excel file.
        response['Content-Disposition'] = 'attachment; filename=books.xls'

        # Create object for the Workbook which is under xlwt library.
        workbook = xlwt.Workbook()

        # By using Workbook object, add the sheet with the name of your choice.
        worksheet = workbook.add_sheet("Books")
     
        row_num = 0
        columns = ['ID', 'Title', 'Description']
        for col_num in range(len(columns)):
            # For each cell in your Excel Sheet, call write function by passing row number, 
            # column number and cell data.
            worksheet.write(row_num, col_num, columns[col_num])     
       
        for book in books:
            row_num += 1
            row = [book.id,book.title,book.description]
            for col_num in range(len(row)):
                worksheet.write(row_num, col_num, row[col_num])
       
        workbook.save(response)
        return response

After filling up the sheet with the data, save the workbook by passing response object as an argument and return response object. Finally the response will be Excel file(books.xls) with all the records in the Book Model.