Contrary to popular belief, building a web scraper doesn't have to be a difficult affair. Even if you don't have advanced knowledge in coding, you can create a web scraper within a few minutes. It'll help you scrape data from a website, and you can use the extracted data to make informed decisions.
To create a web scraper, you require:
a stable internet connection
a computer with Mac or Windows
Basic knowledge of using Python to create a function
In this article, we'll look at how to build a Python web scraper.
What Is a Web Scraper and How Can You Build One?
A web scraper refers to a program that helps you extract data from a website. The program acts as a map that helps you identify the desired data from a website.
You can scrape data from a web page either manually or automatically. Manual data extraction can be demanding and time-consuming. On the other hand, web scrapers automate the data extraction process making it less time-consuming.
You can limit the scraped data to a particular list, topic, or author. The web scraper will help you limit the scope of data extraction using parameters that you feed the program. However, each web scraping project should contain a URL to extract from.
Additionally, the scraper should help you identify the HTML tags that contain the data you want to scrape. Knowing where the data on the web page is will help you save time and resources before you can build the scraper.
Some companies restrict scraping data from their websites. Before you can build a scraper and start extracting data from a website, it'll be helpful to check out the website's terms and conditions.
Generally, scraping data from web pages for commercial purposes isn't allowed. You should also avoid extracting data rapidly as it can cause a website to break.
How Does a Web Scraper Work?
A web scraper helps collect data from a website in the same manner as a human being. The scraper goes to a particular web page and gathers relevant data.
You can then store all the data on a database or JSON file (JavaScript Object Notation).
Each website consists of a different HTML structure. Before you can create a web scraper, it'll be best to check the following:
The structure of the HTML pages with the information you want to extract
How to get to the particular web page
Whether you need to scrape data from the next pages
Some functions of a web scraper can include:
Parsing the URL to access a web page element
fetching image links
getting all the links from a web page
Building a Web Scraper Using Python Code
Using Python to create a web scraper is advantageous since the Python syntax is easy to understand. Creating a code using Python is like making an English statement.
You'll have your Python web scraper up and running within a few minutes.
Setting Up a Python Project
You can download Python on your device by visiting the official website at www.python.org.
After installing Python on your device, you should also choose your text editor. You can choose any text editor among the several choices available online.
You can create a Python code project after you have your text editor and Python code installed on your device. You can create your new project on your favorite location on your computer, including the desktop.
After creating the Python project, you can continue to open a Python file for the web scraper. You can name the py file webscraper.py file.
The data science project will involve scraping the HTML page content, collecting the data, and saving it on JSON. You can then parse the data using Python to scrape the relevant information. Different Python scripts do data extraction and data parsing.
Python Libraries
Setting up your new data science project also involves installing the necessary Python libraries. A Python library is a package that offers enhanced functionality.
Python offers various packages, including selenium, XML, HTML requests, and Beautiful Soup. The HTML requests help you to request URLs to allow you to collect data from the HTML pages.
On the other hand, the Beautiful Soup library helps you identify the HTML tags from the Python script.
It may not be the best idea to install all the packages globally on your device as it can lead to challenges while developing other applications. If you use one version of the library on one application and another on other applications, you'll have challenges running both.
Therefore, it'll be best for you to set up a virtual environment. A virtual environment enables you to use different library versions on separate applications. For instance, you can use HTML Requests library version 1 on an application and Requests version 2 on another application. The separation helps you to avoid conflicts while running the applications.
You can use a pin installer to install the Python libraries on your machine. For instance:
pip install requests
You can import the library onto your Python file.
Note that some Python libraries take up a lot of space on your device and can also take time to download and install.
Requests with Python include three components which are:
- URL: URL refers to a string with the address of the web page you want to scrape. For example www.twitter.com
- Response: the response represents the outcomes of the GET request, and it's an HTTP code
- Content: content consists of the response from the URL request. It features the content of the entire HTML page that you requested.
You can store the scraped data as JSON.
While scraping websites, it's good to find out whether you're scraping from static or dynamic websites. Dynamic websites feature dynamically generated content that isn't readily visible. The Selenium Python library helps get HTML elements from dynamic websites, while Beautiful Soup helps extract data from static websites.
Is it Hard to Create a Web Scraper?
Building a web scraper isn't a difficult process.
As a developer, you have two options:
Create a web scraper that helps extract data from each website
Build a scraper that extracts data from all websites
The first option is challenging as websites keep changing all the time, forcing you to build several scrapers that are time-consuming.
The second option is also difficult as you have to create an HTML code that determines a site's structure and that of each web page.
Although creating a scraper for scraping all websites is possible, it's challenging to maintain high accuracy. It becomes more challenging when you try to scrape dynamic data.
Learning how to extract HTML content from websites also takes a short time. You can learn web scraping within a week. The learning includes data analysis and forms of manipulating data.
How Much Is the Cost of Creating a Web Scraper?
How much it'll cost you to build a web scraper depends on various factors. A company can use several approaches for scraping websites, including:
Building a Scraper on Your Own
If you are a developer, you can create a scraper on your own to cater to your data extraction needs.
Luckily, there are tons of resources online that help you with how to build a scraper using Python or JavaScript code.
However, building a scraper on your own is time-consuming. You have to spend a lot of time fixing bugs and making various improvements.
The costs include data storage, server costs, and IP proxies costs. If you hire a developer, you have to pay for their time creating and maintaining it. The cost of a developer can range between $200 to $1000 per month.
Outsource to Another Party
If your business doesn't have a tech team to help build a scraper, you can opt to outsource the work to a third party.
For instance, you can hire a freelance developer from freelance sites such as Upwork. The cost of a freelance developer varies depending on various factors, including their experience. You can get a freelance developer to help you with your web scraping needs for as low as $30/hour. An experienced freelance developer can charge you even more than $100/hour.
Alternatively, you can outsource the work to a team of experts that come together to form a web scraping agency. The team will charge you depending on the magnitude of the work, but the price can range between $600 to $1000.
Use Web Scraping Tools
Instead of creating a web scraper by yourself, you can decide to use web scraping tools to help you in the process.
A web scraping tool is software designed to collect data online and helps to make data extraction easy. The tools vary in the features they offer and pricing. How much it'll cost you depends on the package you choose.
Most tools offer free plans and trials with limited features. Some also offer premium packages with a flat fee, saving you the trouble of the hourly charges.
Final Word on How to Build a Web Scraper
Building a scraper to help in your data extraction needs isn't that difficult. You can build the scraper without many challenges with basic HTML code basics. Alternatively, you can hire a team of experts or use a freelance developer.
FAQs
1.Can you make a web scraper with C++?
Yes, you can make a web scraper with C++. If you start with a small project and decide that web scraping is for you, most of the code is reusable. A few tweaks here and there, and you'll be ready for much larger data volumes.
2. Why web scraping is difficult?
There was a time when you had to create separate web scrapers for yourself in order to scrape data from data since it took a long time to do it manually. In order to create the best data scrapers, one must master a variety of programming languages.
3. Which language is fastest for web scraping?
The fastest language for web scraping is Python. The best language for web crawler is PHP, Ruby, C and C++, and Node. JS.
