Python 3 script for downloading all the pages of the webcomic On a Sunbeam (http://www.onasunbeam.com/). Requires Requests (http://docs.python-requests.org/) and Beautiful Soup 4 (https://www.crummy.com/software/BeautifulSoup/).

get_sunbeam.py

#!/usr/bin/env python3
'''Dowload the comic *On a Sunbeam*'''
import shutil
from urllib.parse import urljoin, urlparse
from os.path import basename
import requests
from bs4 import BeautifulSoup


def get_chapter_links(url):
    '''Yield the links from the html at `url` that start with "chapter".'''
    homepage_response = requests.get(url)
    soup = BeautifulSoup(homepage_response.text, 'html.parser')
    link_elements = soup.find_all('a')

    for link_element in link_elements:
        if link_element.get('href').startswith('chapter'):
            yield urljoin(url, link_element.get('href'))


def get_chapter_image_links(url, homepage):
    '''
    Yield the urls of images from the html at `url` from the website root
    `homepage`.

    The images are from `<img>` elements with the class of `chapter-page` and
    the urls are in the `data-original` attribute.
    '''
    chapter_response = requests.get(url)
    soup = BeautifulSoup(chapter_response.text, 'html.parser')
    chapter_img_elements = soup.find_all('img', class_='chapter-page')

    for chapter_img_element in chapter_img_elements:
        yield urljoin(homepage, chapter_img_element.get('data-original'))


def download_file(url, destination, log=False):
    '''
    Download the file at `url` to `destination`.

    Source: https://stackoverflow.com/a/13137873
    '''
    response = requests.get(url, stream=True)
    if log:
        print('Downloading {} to {}'.format(url, destination))

    if response.status_code != 200:
        raise Exception(
            'Request to {url} returned status code: {code} {reason}'.format(
                url=response.url,
                code=response.status_code,
                reason=response.reason
            )
        )

    with open(destination, 'wb') as destination_file:
        response.raw.decode_content = True
        shutil.copyfileobj(response.raw, destination_file)


def download_sunbeam(homepage):
    '''
    Download all the pages of *On a Sunbeam* to the current directory.

    `homepage` is the homepage of the comic.
    '''
    for chapter_link in get_chapter_links(homepage):
        for chapter_image_link in get_chapter_image_links(chapter_link, homepage):  # noqa: E501
            filename = basename(urlparse(chapter_image_link).path)
            download_file(chapter_image_link, filename, log=True)


if __name__ == '__main__':
    download_sunbeam('http://www.onasunbeam.com/')