very-simple-scraper v0.2.0

Very Simple Scraper

Overview

This repo contains a scraper and parser that both work on a specified input csv file. First you scrape the rows in the file. Then you parse the scraped response associated with each row. The parse command generates a parse session folder. In this folder you will find files associated with extracted data, missing data, and new inputs.

Initial setup

npm i very-simple-scraper

const scraper = require('very-simple-scraper').scraper;
const domains = require("./domains");

const formProxyUrl = (urlToScrape, apiKey) =>
  `https://someproxyservice/?key=${apiKey}&url=${urlToScrape}`;

scraper(domains, formProxyUrl)

Inputs

The input csv file requires that you have a domain, kind, and id header.

Make sure the csv file has the headers present as the first line of the file

domain,kind,id
wikipedia,homepage,''
wikipedia,wiki,Ever_Given
wikipedia,wiki,COVID-19_pandemic

Optionally, you may also provide a originDomain, originKind, originId, and context.

You can use the filter option below to filter on specific contexts.

When you generate parse session output, you will often see a inputs.csv file in the folder. This file contains inputs found when parsing whatever data you ran it over. It is common to use this new inputs.csv as a input for a brand new scrape and parse session.

Scraping

Data is scraped from a domain and saved in a local html cache folder. Data in this folder can than be parsed with the other command.

Args

You must specify: token and input command line arguments.

• token : the ScrapingBee token
• input : the input csv file. A header with url must exist in this file.

You may specify: from, to, filter, and parallelize command line argument.

• from : start at the from row number in the input CSV. Ex: --from=10
• to : end at the to row number in the input CSV. Ex: --to=90
• filter: Filter by a domain kind's context. Ex: --filter="wiki link". Filters can use the union operator. For example: --filter="wiki link|reference link"
• parallelize: run the scraper in Tmux in N parallel sessions. Each session is a window named after the chunk it is processing. Ex: --parallelize=3 will run 3 sessions. If there are 9 rows, the windows will be named 0-2, 3-5, and 6-8.

Example

node run.js scrape --token=MYTOKEN --input=input.csv --to=5

Parsing

Args

You must specify: input and output command line arguments.

• input : the input csv file. A header with url must exist in this file.
• session : the output session name. Output files will be written to scraped/output/<session name>/*

You may specify: from, to and filter command line argument.

• from : start at the from row number in the input CSV. Ex: --from=10
• to : end at the to row number in the input CSV. Ex: --to=90
• filter: Filter by a domain kind's context. Ex: --filter="wiki link". Filters can use the union operator. For example: --filter="wiki link|reference link"

Examples

Parse the fist 500 rows of a CSV

node run.js parse --input=input.csv --session=wiki_data_apr_1 --to=500

Parse the first 10 rows and filter for rows that have the context tag media

node run.js parse --input=scraped/output/out2/inputs.csv --session=out3 --to=10 --filter="reference link"

Scrape rows 20 to 100 across 10 sessions in parallel

node run.js scrape --token=TKM0D87U1XR98JD0F74RMULE7GMLYDVY2O --input=input.csv --from=20 --to=100 --parallelize=10

Scrape everything in the input csv across 10 sessions in parallel

node run.js scrape --token=TKM0D87U1XR98JD0F74RMULE7GMLYDVY2O --input=input.csv --parallelize=10