htmlLibrarian

Installation

sudo pip3 install htmlLibrarian

Introduction

The goal of this package is to almost be like a training wheels setup for web scraping.

A good example is recursively trying to visit all of the links on a site such as:

http://web.archive.org/web/20080827084856/http://www.nanowerk.com:80/nanotechnology/nanomaterial/commercial_all.php?page=2

If you mess up your scrape and you have done no preemptive measures, you lose all of your work done thus far. What Librarian aims to do is to save that html for later, so you don't have to redo scrapes that you have done before, letting you be much nicer to where you're requesting to and saving you time, letting you go through a much smoother scraping experience.

Usage

Let's outline an example:

Take a look at the site above's html via Inspect Element; You will see that all of the names and links are under <div class="divhead">, and all of the blurbs are under <div class="divline">. Now, I would probably do this:

from urllib.request import urlopen
from bs4 import BeautifulSoup

alink = 'http://web.archive.org/web/20080827084856/http://www.nanowerk.com:80/nanotechnology/nanomaterial/commercial_all.php?page=2'
resp = urlopen(alink)
html = resp.read()
soup = BeautifulSoup(html, 'lxml')

for elem in soup.select('div.divhead'):
    print(elem.get_text())

To check if I was correct and there was nothing above that had the same css selector, to see if I had to change my headers using urllib.request.Request, or something else. Then I'd probably check the same for div.divline, for the first reason above. Then for each of those sites, I'd have to recursively visit into them and grab their html.

If I screw anything up, or if some pages have different html, then it will take a long time to get back to where I was, making the process of scraping a site more painful than it has to be.

If we use Librarian, we can instead do this:

from htmlLibrarian import Librarian

lib = Librarian()

alink = 'http://web.archive.org/web/20080827084856/http://www.nanowerk.com:80/nanotechnology/nanomaterial/commercial_all.php?page=2'

html = lib.get(alink).get_html()
soup = BeautifulSoup(html, 'lxml')

Now, if I ever ask for that same website again (provided that htmlLibrary and the pickled files under libarianTools haven't been tampered with), the Librarian will find it and pull it out of your htmlLibrary so you can instantly use it.

If you need updated html, just

from htmlLibrarian import Librarian

lib = Librarian()

alink = 'http://web.archive.org/web/20080827084856/http://www.nanowerk.com:80/nanotechnology/nanomaterial/commercial_all.php?page=2'

newhtml = lib.fetch(alink).get_html()

lib.fetch(alink) will go and fetch the newest html and it will return a dataLink object.

If you want to see your older scrapes, just

from htmlLibrarian import Librarian

lib = Librarian()

alink = 'https://https://ca.indeed.com/jobs?q=data+scientist&l='
dataLinkList = lib.get_all(alink)

lib.remove(alink) will remove the dataLinks associated with alink from your htmlLibrary and linkMap.

This project is in it's infancy so if you want any features created, create an issue and I will get on it.

Thank you to keithreitz for creating samplemod, which I largely copied for the project structure.