R Web Scraping Quick Start Guide / Aydin, Olgun.

Format:

Book

Author/Creator:

Aydin, Olgun, author.

Language:

English

Subjects (All):

R (Computer program language).

Physical Description:

1 online resource (114 pages)

Edition:

1st edition

Place of Publication:

Packt Publishing, 2018.

System Details:

text file

Summary:

Web Scraping techniques are getting more popular, since data is as valuable as oil in 21st century. Through this book get some key knowledge about using XPath, regEX; web scraping libraries for R like rvest and RSelenium technologies. Key Features Techniques, tools and frameworks for web scraping with R Scrape data effortlessly from a variety of websites Learn how to selectively choose the data to scrape, and build your dataset Book Description Web scraping is a technique to extract data from websites. It simulates the behavior of a website user to turn the website itself into a web service to retrieve or introduce new data. This book gives you all you need to get started with scraping web pages using R programming. You will learn about the rules of RegEx and Xpath, key components for scraping website data. We will show you web scraping techniques, methodologies, and frameworks. With this book's guidance, you will become comfortable with the tools to write and test RegEx and XPath rules. We will focus on examples of dynamic websites for scraping data and how to implement the techniques learned. You will learn how to collect URLs and then create XPath rules for your first web scraping script using rvest library. From the data you collect, you will be able to calculate the statistics and create R plots to visualize them. Finally, you will discover how to use Selenium drivers with R for more sophisticated scraping. You will create AWS instances and use R to connect a PostgreSQL database hosted on AWS. By the end of the book, you will be sufficiently confident to create end-to-end web scraping systems using R. What you will learn Write and create regEX rules Write XPath rules to query your data Learn how web scraping methods work Use rvest to crawl web pages Store data retrieved from the web Learn the key uses of Rselenium to scrape data Who this book is for This book is for R programmers who want to get started quickly with web scraping, as well as data analysts who want to learn scraping using R. Basic knowledge of R is all you need to get started with this book.

Contents:

Cover

Title Page

Copyright and Credits

Dedication

Packt Upsell

Contributors

Table of Contents

Preface

Chapter 1: Introduction to Web Scraping

Learning about data on the internet

Introduction to XPath (XML Path)

Data extraction systems

Web scraping techniques

Traditional copy and paste

Text grabbing and regular expression

Document Object Model (DOM)

Semantic annotation recognition

Web scraping tools

JavaScript tools

Web crawling frameworks

Web crawling environment in R

Summary

Chapter 2: XML Path Language and Regular Expression Language

XML Path (XPath)

Nodes

Relationships between nodes

Parent

Child

Sibling

Ancestor

Descendant

Predicates

Selecting unknown nodes

Selecting several paths

Regular expression language (Regex)

How to match a single character

How to match the characters of a set

How to match words

Exercises on RegEx and XPath

RegEx exercises

XPath exercises

Chapter 3: Web Scraping with rvest

Introducing rvest

Step-by-step web scraping with rvest

Writing XPath rules

Writing your first scraping script

Playing with data

Chapter 4: Web Scraping with Rselenium

Advantages and disadvantages of using Selenium for web scraping

RSelenium

Step-by-step web scraping with RSelenium

Collecting data with RSelenium

Chapter 5: Storing Data and Creating Cronjob

Cloud engine models

Infrastructure as a service (IaaS)

Platform as a service (PaaS)

Software as a service (SaaS)

Mobile backend as a service (MBaaS)

Function as a service (FaaS)

Some of the cloud services

Amazon Web Services (AWS)

Google Cloud

Cronjob

Storing data and creating schedule jobs for web scraping

Creating an AWS RDS Instance.

Connecting to the PostgreSQL database on AWS

Creating cronjob

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Index.

Notes:

Online resource; Title from title page (viewed October 31, 2018)

OCLC:

1081335525