![]() ![]() Finally, the SAX model just allows for read-only parsing. SAX is also inconvenient for handling deeply nested elements. However, finding or modifying random tree nodes is cumbersome because it usually requires multiple passes on the document and tracking the visited nodes. This means it has a much lower memory footprint than DOM and can deal with arbitrarily large files, which is great for single-pass processing such as indexing, conversion to other formats, and so on. SAX also lets you discard elements if you’re not interested in them. This approach is known as “push” parsing because elements are pushed to your functions by the parser. The parser triggers user-defined callbacks to handle specific XML nodes as it finds them in the document. The end result was an event-based streaming API that operates sequentially on individual elements rather than the whole tree.Įlements are processed from top to bottom in the same order they appear in the document. There was no formal specification, only organic discussions on a mailing list. To address the shortcomings of the DOM, the Java community came up with a library through a collaborative effort, which then became an alternative model for parsing XML in other languages. Some typical use cases are when you need to parse a relatively small document or when you only need to do the parsing infrequently. ![]() Use a DOM parser when convenience is more important than processing time and when memory is not an issue. This renders the DOM suitable only for moderately large configuration files rather than multi-gigabyte XML databases. Moreover, the XML gets parsed at once, as a whole, so it has to be reasonably small to fit the available memory. While the DOM tree allows for fast and omnidirectional navigation, building its abstract representation in the first place can be time-consuming. An abstract representation of the entire document tree is stored in memory, giving you random access to the individual elements. It defines a handful of standard operations for traversing and modifying document elements arranged in a hierarchy of objects. The DOM is arguably the most straightforward and versatile model to use. Both XML and HTML belong to the same family of markup languages, which makes parsing XML with the DOM possible. #Aasync xmlreader codeYou might have already heard about the DOM because web browsers expose a DOM interface through JavaScript to let you manipulate the HTML code of your websites. Historically, the first and the most widespread model for parsing XML has been the DOM, or the Document Object Model, originally defined by the World Wide Web Consortium (W3C). #Aasync xmlreader how toTo get the most out of this tutorial, you should already be familiar with XML and its building blocks, as well as how to work with files in Python. By the end of it, you’ll be able to pick the right XML parser for a given problem. You can use this tutorial as a roadmap to guide you through the confusing world of XML parsers in Python. Use safe XML parsers to eliminate security vulnerabilities. ![]()
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