Simplify Asynchronous Web Scraping With Python and AIOHTTP
Data is an undisputed commodity in today’s business landscape. The staggering amount of data created every day contains a multitude of unexplored opportunities for people who can extract the right insights from it. Unfortunately, most of this data is unstructured and difficult to access, which limits its potential. Fortunately, web scraping allows you to harness the power of unstructured data so your business can gain a competitive advantage in a rapidly evolving environment.
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Web scraping and API scraping
Web scraping is the process of using an automated script (a bot) to extract unstructured data from web pages and export it into a format that you can understand and use, usually a JSON file or spreadsheet. You can then analyze this data for trends to make strategic business decisions or for surprising connections. Web scraping allows you to give structure and meaning to the endless amount of information freely available on the internet.
While web scraping may have been a questionable practice in the past, it’s an accepted part of all industries today. However, it’s not always a harmless practice. Unethical scraping practices can overload a site and cause it to crash. As a result, many websites implement anti-bot security measures designed to derail your web scraper.
Other websites recognize the value of allowing web scraping but don’t want bots to interfere with their performance. These sites provide an application programming interface (API) to allow you access to their data without tying up their server resources dealing with scraping bots. APIs also allow developers to build applications using a common data set.
Whenever a website has an API that provides the data you need, you should always collect data through it instead of scraping the site. It’s much more efficient and produces less impact on your target website. An excellent example of a web scraping API is Scraping Robot’s API, which exposes a single API endpoint so you can get the data you need by sending your API key and an HTTP request to https://api.scrapingrobot.com.
What is asynchronous web scraping?
Despite its many benefits, there are some drawbacks to traditional web scraping. While it’s much faster and uses far fewer resources than manually extracting data, web scraping is still a complex process. Although some websites offer APIs, many do not. Also, there are times the data you need isn’t included in the API. Unstructured data is notoriously messy, meaning you often have to continuously loop over multiple pages with various extraction tools. If you’re extracting the large amounts of data you need to spot trends and gain a competitive business advantage, it can be a lengthy process.
If you program a synchronous web scraper to scrape multiple sites, it will run one request at a time. It will scrape one URL and then proceed to the next when the first one is finished. To accomplish this orderly task, Python requests wait for the page to load, and the code blocks another task from starting before the previous one is completely finished.
Asynchronous web scrapers run on asynchronous code — which is also called nonblocking or concurrent code. Asynchronous code pauses while waiting for a response. During these pauses, other routines can run, unlike with synchronous code, which won’t let other routines run until its routine is complete. Since much of a web scraper’s run time is spent waiting for a response, this ability to pause makes for a much faster and more efficient web scraper.
Asynchronous web scraping with AIOHTTP and Python
AIOHTTP is a client- and server-side library that lets you create asynchronous code. You can program asynchronous code in Python with ASYNCIO requests, which pause when inactive to allow active routines to run. These are called coroutines and can make a significant difference in how fast your scraper performs. The AIOHTTP library provides even more specific functionality within ASYNCIO for HTTP requests, making it easier to build a web scraper with asynchronous code.
When you create a program that depends on a response from another site in synchronous code, it executes like this:
- Request: wait: response
- Request: wait: response
- Request: wait: response
When you create a program in asynchronous code that depends on a response from another site, it may look more like this:
- Request: request: request
- Response: response
- Request: response: response
During the wait times, the program can send out other requests, effectively eliminating the wait time.
You’ll need to download the AIOHTTP and ASYNCIO libraries and set up coroutines to run concurrently. This video AIOHTTP tutorial will walk you through the process of coding a simple asynchronous web scraper. While it’s easy enough to create a scalable Python asynchronous scraper, you’ll still need to deal with anti-bot security measures on the sites you scrape.
Beginning developers can follow a Python ASYNCIO tutorial and create a workable web scraper. In fact, this is a great project for someone who is learning to code or wants to dip their toes into data analysis by scraping their own data. Unfortunately, the true headaches in web scraping aren’t related to building a scraper. Even experienced developers don’t usually want to deal with the hassles of building and maintaining a web scraper, regardless of whether it’s synchronous or asynchronous.
Problems with asynchronous Python web scrapers
The biggest reason developers don’t want to handle web scrapers is because of the anti-bot technology most websites employ. Anti-bot measures are a constant game of cat and mouse between websites and bots. As soon as you figure out how to get around a website’s automated bot blocker, it implements another trap. Staying on top of anti-bot technology is almost a full-time job in itself, particularly if you’re scraping massive amounts of data for business purposes.
Some of the most common anti-bot measures your scraper will encounter are:
IP blocks
Almost all websites automatically block an IP address that issues too many requests too quickly. Since human hands can only type so fast — and even the slowest synchronous web scraper can issue requests at a much faster pace — multiple requests spaced closely together are a sure sign of a bot at work. To block web scrapers and other bots with less noble intents, websites use a program that automatically blocks any IP address that displays this behavior. You can get around this using proxies, but proxy management can be a hassle as well.
CAPTCHAs
CAPTCHAs are another roadblock for web scrapers. Even if you use proxies and avoid triggering automatic blocks, if a site thinks you’re suspicious, it’ll throw up a CAPTCHA for you to solve. These are a pain for web scrapers because they have to be solved before they can continue scraping. Humans are much better at solving CAPTCHAs than robots, so this can be an effective block.
Other anti-scraping updates
While IP bans and CAPTCHAs are two of the most common anti-scraping measures websites employ, new methods are constantly being created. Avoiding anti-scraping traps generally involves making your scraper act as human as possible while not slowing it to a crawl. Therein lies the true challenge in effective scraping.
Solving web scraping challenges with Scraping Robot
At Scraping Robot, we think of these challenges as puzzles we enjoy solving. We could happily talk about proxy management all day long. Rotating proxies, ISP proxies, data center proxies? We consider IP bans an excuse to show off our amazing rotating proxy speed. However, we realize that not everyone geeks out on scraping challenges the way we do.
We know that the most important aspect of web scraping for you is the invaluable data you get that can launch your next big business venture or let you spot a trend to inspire your next new product. That’s why we created Scraping Robot. Scraping Robot is a plug-and-play solution that lets you mine for data without dealing with issues such as:
- IP bans
- Proxy management
- CAPTCHA
- Browser scalability
- Server management
- Changes in website structure
Instead, all you have to do is plug in our API to get up and running in minutes. You’ll get structured JSON output of your target website’s parsed metadata in no time. Scraping Robot can extract data from thousands of websites in minutes. Instead of hiring extra developers to create solutions for you, you can cut down on your hiring expenses and increase your efficiency.
Scraping Robot is an easy, elegant solution when you need data to work for you. With Scraping Robot, you’ll get:
- Automatic metadata parsing
- Graphs of your scraping activity over the past day, week, and month, beautifully illustrating your progress
- Easy access to records of your previous results
Scraping Robot offers an affordable plan at two different tiers. You can sign up for a free account to give us a try. You’ll get 5,000 scrapes per month, and you’ll have access to our top-notch features, including:
- 24/7/365 customer support
- New modules that are added monthly
- Frequent updates
- Seven-day storage
Sign up for a free account today, or reach out if you have any questions.
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