Creating your First Spider

In this tutorial, we will walk through the creation of your first spider using Scrapy, a powerful and flexible web scraping framework. We will begin with what a spider is, and then proceed to create a simple spider.

What is a Spider?

In Scrapy, a Spider is a class that defines how to perform the web scraping, including how to navigate and extract data from a website. In other words, it's our crawler's blueprint.

Setting Up Your Environment

Before we start, make sure you have installed Scrapy. If not, you can install it using pip:

pip install scrapy

Creating a Scrapy Project

First, we need to create a new Scrapy project. Navigate to your directory of choice, and run the following command:

scrapy startproject myspider

This will create a new directory "myspider" with the basic structure of a Scrapy project.

Creating a Spider

Navigate into the myspider directory, and under the spiders subdirectory, create a new Python file. For the purpose of this tutorial, we'll name it quotes_spider.py. This is where we'll define our spider.

Coding the Spider

In quotes_spider.py, write the following code:

import scrapy

class QuotesSpider(scrapy.Spider):
    name = "quotes"

    def start_requests(self):
        urls = [
            'http://quotes.toscrape.com/page/1/',
        ]
        for url in urls:
            yield scrapy.Request(url=url, callback=self.parse)

    def parse(self, response):
        page = response.url.split("/")[-2]
        filename = f'quotes-{page}.html'
        with open(filename, 'wb') as f:
            f.write(response.body)
        self.log(f'Saved file {filename}')

Here's what's happening:

We import Scrapy and define our spider class QuotesSpider which inherits from scrapy.Spider.
We give our spider a name "quotes" to identify it.
The start_requests method generates the initial requests. In this case, we're requesting "http://quotes.toscrape.com/page/1/".
The parse method will be called with the response of the request as its argument. Here, we save the page to a local file.

Running the Spider

You can now run your spider using the scrapy crawl command, followed by the name of the spider:

scrapy crawl quotes

This will crawl the quotes website and store the content of each page in a separate file.

And there you have it! You've created your first Scrapy spider. Remember, this is a simple example. Scrapy spiders can be customized extensively to suit your specific needs. You can define how to follow links in the pages, how to parse the data, and much more. Happy crawling!

Creating your First Spider