How do Item Loaders work?
So far we know, Item Loaders are used to parse, the data, before Item fields are populated. Let us understand, how Item Loaders work –
- Item loaders, help in populating, the scraped data, into Scrapy Items. The Items are fields, defined in the ‘items.py’ file.
- An Item Loader will have one input processor, and, one output processor, defined for each Item field.
- We know, Scrapy makes use of Selectors, which are XPath or CSS expressions, to navigate to the desired HTML tag.
- The Item loader, uses, its add_xpath() or add_css() methods, to fetch the data desired.
- The Input processors, then act on this data. We can mention, our custom functions, as parameters, to input processors, to parse, the data as we want.
- The result, of the input processor, is stored in the ItemLoader.
- Once, all the data is received, and, parsed, according to input_processor, the loader will call, its load_item() method, to populate the Item object.
- During this process, the output processor is called, and, it acts on that intermediate data.
- The result of the output processor is assigned to the Item object.
- This is how, parsed Item objects, are yielded.
Scrapy – Item Loaders
In this article, we are going to discuss Item Loaders in Scrapy.
Scrapy is used for extracting data, using spiders, that crawl through the website. The obtained data can also be processed, in the form, of Scrapy Items. The Item Loaders play a significant role, in parsing the data, before populating the Item fields. In this article, we will learn about Item Loaders.
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