Download all open Springer ebooks

springer.py

#!/usr/bin/env python
'''
Springer has released some ebooks freely in order to support learning during
these times of lockdown with the COVID-19 spreading.
Source: https://www.springernature.com/gp/librarians/news-events/all-news-articles/industry-news-initiatives/free-access-to-textbooks-for-institutions-affected-by-coronaviru/17855960

A spreadsheet containing the URLs of all available books can be found on the
aforementioned page. These URLs have been hardcoded below. And this script
lets you download all books automatically.

Dependencies:
- aiohttp==3.6.2
- beautifulsoup4==4.9.0
- lxml==4.5.0
- Unidecode==1.1.1
'''

from string import punctuation, whitespace
from typing import List, Tuple
import asyncio
import os
from bs4 import BeautifulSoup
from unidecode import unidecode
import aiohttp


URLS = [
    'http://link.springer.com/openurl?genre=book&isbn=978-0-306-48048-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-306-48247-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-21736-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-22592-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-21777-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-28117-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-24158-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-32353-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-36218-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-36274-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-36601-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-37575-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-40065-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-45524-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-46271-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-46312-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-49312-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-68566-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-72071-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-72579-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-74365-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-75959-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-76501-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-77650-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-78341-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-79054-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-84858-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-87573-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-88698-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-88963-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-93837-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4020-5719-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4020-6099-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4020-6808-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-35963-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-662-44874-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-03762-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-56194-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-0400-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-27877-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-44794-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4419-9479-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-18842-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-48936-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-21239-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-7091-0715-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4419-6488-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-01851-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4939-3058-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-26551-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-662-46321-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-13072-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-4556-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4615-1077-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-02099-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-37434-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-981-10-2045-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-57040-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-23042-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-53883-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-90-481-2516-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4899-7454-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-662-53785-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-51118-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-57589-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4419-1120-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-23026-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-44738-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-05699-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-47831-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-31791-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-54083-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4612-1844-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-84800-070-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-19864-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-61088-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-46162-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-33916-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-32862-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-30250-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4939-1194-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4613-0139-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-54064-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-7116-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-43341-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4419-0641-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4419-5653-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-12682-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4471-7307-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-662-53045-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-33143-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-31089-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-12742-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-52250-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4471-5134-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-28887-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4419-9504-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-662-45171-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-8349-6331-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-84882-935-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-07806-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-14142-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-37314-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-20951-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-50091-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-540-77974-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-19596-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-662-53022-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4471-4474-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-54413-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-37902-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-46394-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4939-6374-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4612-4374-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-59731-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-22309-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-30319-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-2212-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-662-49887-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-94-007-5757-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-14941-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4939-2122-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-58307-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-6271-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-21936-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-09351-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-21990-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-9170-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-55309-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4471-5201-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4939-2614-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-20451-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4612-4360-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-09171-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-94-007-1171-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-23012-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-4809-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4419-0925-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-658-07884-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-27265-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-57883-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-31650-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-01195-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-54349-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-662-43715-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-981-4560-67-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-23428-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-94-007-1211-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-27104-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-55444-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-63913-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-44561-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-34132-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-3954-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-29854-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-55615-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-46407-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4419-9982-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-53919-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-24551-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-981-10-1802-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4471-6419-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4939-6572-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-84800-322-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-6940-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4612-0979-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-11080-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-30304-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-29716-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-04101-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-24346-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4613-0041-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4939-2712-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-540-76504-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-7630-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-33405-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-31036-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4939-1151-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-40975-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-3618-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-10091-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-3523-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-62872-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-56475-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-5538-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-00401-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-03623-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-19464-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-20556-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-6227-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-54398-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-15018-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-94-017-8771-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4939-2113-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-22951-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-4-431-54526-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4419-6646-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-65867-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-7138-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-00894-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-44048-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-12493-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-9236-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-981-287-212-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-28980-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-29791-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-84628-642-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-20059-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-51412-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-20600-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-19425-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-662-54817-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-44127-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-6786-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-24331-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-50651-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-662-54486-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-3987-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-540-93804-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-8933-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-50319-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-39439-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-57750-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-05290-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-01769-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-94-007-6863-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4939-0867-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-84628-168-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4419-7288-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-540-69934-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-49810-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-14240-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-21173-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-658-10183-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-45776-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4939-1911-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-15195-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-7807-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4757-0576-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-29659-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-6486-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4471-6642-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4899-7550-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-540-32899-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-24280-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-3143-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-19587-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4939-2623-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-540-27752-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-50017-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-7946-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-61185-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-662-46950-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-18539-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-16874-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-25970-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-6849-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-34195-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-94-017-7242-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-15666-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-23880-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-49875-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-18398-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-94-007-6113-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4939-2766-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-2197-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-14777-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-9138-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4612-1272-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4471-5361-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4471-5601-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4471-6684-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-9126-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4757-2519-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-55606-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-57252-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-25675-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-8687-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-642-20144-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4614-4262-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-44899-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-0-387-71481-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-14454-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-48848-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-49849-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-58715-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-64786-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-65451-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-981-10-5218-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4939-6676-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-61158-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-66631-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-70920-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-70790-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-63133-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-662-49279-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-64410-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-66772-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-68588-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-68598-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-72547-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-58487-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-67395-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-65439-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-73004-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-66219-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-75771-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-73123-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-94-024-1144-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-662-56272-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-662-56509-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-68834-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-73132-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-65094-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-72682-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-59978-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-65682-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-77649-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-76442-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-78729-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-349-95348-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-68301-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-78361-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-77809-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-662-55381-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-77425-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-981-13-0399-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-91041-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-74965-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-662-57265-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-981-13-1090-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-78181-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-89491-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-91722-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-72911-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-91575-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-92207-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-95381-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-63588-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-91890-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-89292-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-72314-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-75502-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-75708-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-92804-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-94463-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-72347-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-92429-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-95762-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-92333-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-981-13-2475-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-662-56707-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-94313-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-98833-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-97298-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-02405-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-77434-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-91155-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-96622-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-96713-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-00581-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-981-10-8297-9',
    'http://link.springer.com/openurl?genre=book&isbn=978-981-10-8321-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-981-13-0785-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-75804-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-99516-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-99118-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-02604-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-03255-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-94743-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-981-13-2023-1',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-00464-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-77315-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-00467-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-01279-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-04516-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-99420-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-71288-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-72000-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-05609-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-74373-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-96337-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-05900-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-981-13-6643-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-10552-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-98875-7',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-12489-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-981-13-3621-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-74746-0',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-13005-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-13605-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-00710-2',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-12727-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-13020-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-15671-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-11117-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-15224-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-18435-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-13788-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-319-68837-4',
    'http://link.springer.com/openurl?genre=book&isbn=978-981-13-7496-8',
    'http://link.springer.com/openurl?genre=book&isbn=978-981-13-8759-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-19182-5',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-20290-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-030-25943-3',
    'http://link.springer.com/openurl?genre=book&isbn=978-1-4939-9621-6',
    'http://link.springer.com/openurl?genre=book&isbn=978-3-662-56233-8',
]


BASE_URL = 'https://link.springer.com'
CHUNK_SIZE = int(os.environ.get('CHUNK_SIZE', 2 ** 19))  # In bytes. 2**19 = 524288 ~= 500KB
NUM_WORKERS = int(os.environ.get('NUM_WORKERS', 4))
TIMEOUT = int(os.environ.get('TIMEOUT', 10 * 60))  # In seconds. Per request.


def main():
    loop = asyncio.get_event_loop()
    future = asyncio.ensure_future(download_books())
    loop.run_until_complete(future)

async def download_books():
    tasks = []
    semaphore = asyncio.Semaphore(NUM_WORKERS)
    timeout = aiohttp.ClientTimeout(total=TIMEOUT)
    async with aiohttp.ClientSession(timeout=timeout) as session:
        for url in URLS:
            for file_url, filename in await get_file_urls(url, session):
                task = asyncio.create_task(throttled(semaphore, download_book, file_url, filename, session))
                tasks.append(task)
        await asyncio.gather(*tasks, return_exceptions=True)
        print('Downloaded %d files.' % len(tasks))

async def get_file_urls(url: str, session) -> List[Tuple[str, str]]:
    html = await get_html(url, session)
    soup = BeautifulSoup(html, features='lxml')
    hrefs = {a['href'] for a in soup.find_all('a') if is_epub(a) or is_pdf(a)}
    isbn = get_isbn(url)
    return [(BASE_URL + href, get_filename(href, isbn, soup)) for href in hrefs]

async def get_html(url: str, session) -> str:
    async with session.get(url) as response:
        return await response.text()

is_epub = lambda a: a['href'].endswith('.epub') and a.get('title', '').startswith('Download this book')
is_pdf = lambda a: a['href'].endswith('.pdf') and a.get('title', '').startswith('Download this book')
get_isbn = lambda url: url.split('=')[-1].strip()

def get_filename(url: str, isbn: str, soup) -> str:
    return '%s__by_%s__isbn_%s.%s' % (get_title(soup), get_authors(soup), isbn, get_extension(url))

def get_title(soup) -> str:
    return sanitise(soup.find('div', 'page-title').text)

def get_authors(soup) -> str:
    authors = [sanitise(span.text) for span in soup.find_all('span', 'authors__name')]
    return authors[0] if len(authors) == 1 else '_and_'.join(authors)

def sanitise(s: str) -> str:
    s = s.strip().lower().replace('†', '').replace('®', '').replace('\'', '').replace('’', '')
    s = s.translate(str.maketrans(punctuation, ' ' * len(punctuation)))
    s = s.translate(str.maketrans(whitespace, ' ' * len(whitespace)))
    s = s.replace('\xa0', ' ').replace(' ', '_').replace('__', '_')
    return unidecode(s)

get_extension = lambda url: url.split('/')[-1].split('.')[-1]

async def throttled(semaphore, func, *args, **kwargs):
    async with semaphore:
        await func(*args, **kwargs)

async def download_book(url: str, filename: str, session) -> None:
    if os.path.exists(filename):
        print('Skipped %s as %s already exists' % (url, filename))
    else:
        print('Downloading %s as %s' % (url, filename))
        async with session.get(url) as resp:
            with open(filename, 'wb') as f:
                while True:
                    chunk = await resp.content.read(CHUNK_SIZE)
                    if not chunk:
                        break
                    f.write(chunk)
        print('Downloaded %s as %s' % (url, filename))


if __name__ == '__main__':
    main()

Time & Space:

$ time ./springer.py
[...]
Downloaded 736 files.
real	164m44.839s
user	14m16.962s
sys	4m0.892s

$ du -sh .
 16G	.

To check PDF files' validity once downloaded:

$ docker run -v $(pwd):/tmp/books -it ubuntu

# cd /tmp/books
# apt-get update

## Check PDF files using pdfinfo:
# apt-get install -y poppler-utils
# for f in $(ls *.pdf) ; do pdfinfo "${f}" &>/dev/null || echo "${f} is corrupted" ; done

## Check PDF files using qpdf:
# apt-get install -y qpdf
# for f in $(ls *.pdf) ; do qpdf --check "${f}" &>/dev/null || echo "${f} is corrupted" ; done

## Check PDF files using jhove:
# apt-get install -y jhove less default-jre
### Stricter version:
# for f in $(ls *.pdf) ; do [[ $(jhove -m pdf-hul "${f}" | grep -a "Status:") == *"Well-Formed and valid"* ]] || echo "${f} is corrupted" ; done
### Laxer version:
# for f in $(ls *.pdf) ; do [[ $(jhove -m pdf-hul "${f}" | grep -a "Status:") == *"Well-Formed"* ]] || echo "${f} is corrupted" ; done
### To investigate issues:
# jhove -m pdf-hul "${f}" | grep -a "Status:"
# jhove -m pdf-hul "${f}" | grep -a "ErrorMessage:"
# jhove -m pdf-hul "${f}" | less