I will just focus on DTDs for a formats with a fixed simple structure.It is just a set of basic rules, and definitely not exhaustive nor usable for complex DTD design.I have an XML file and an XML schema in another file and I'd like to validate that my XML file adheres to the schema. I'd prefer something using the standard library, but I can install a third-party package if necessary. Surprisingly there aren't many python XML libraries that support this. Not always the best reason to consider one package over another, but I think it is justified in this lxml import etree, objectify from lxml.etree import XMLSyntax Error def xml_validator(some_xml_string, xsd_file='/path/to/my_schema_file.xsd'): try: schema = etree. The page also lists how to use lxml to validate with other schema types. Looks like most of these state they are incomplete, and they seem somewhat "dead." pyxsd last updated in 2006, minixsv last updated in 2008, XSV in 2007 as far as I can tell. This is a description of the content for a family of XML files.Validation is the process of checking a document against a DTD (more generally against a set of construction rules).The validation process and building DTDs are the two most difficult parts of the XML life cycle.Briefly a DTD defines all the possible elements to be found within your document, what is the formal shape of your document tree (by defining the allowed content of an element; either text, a regular expression for the allowed list of children, or mixed content i.e. The DTD also defines the valid attributes for all elements and the types of those attributes.

This is part of the XML 1.0 specification, and allows one to describe and verify that a given document instance conforms to the set of rules detailing its structure and content.HTML is a markup language written in SGML — an "SGML application", to use the terminology.You don't actually have to know much about SGML to use The Validator successfully.HTML browsers are allowed to display HTML documents with errors (like missing end tags). A "well formed" XML document is not the same as a "valid" XML document. In addition, it must conform to a document type definition.XML validation is the process of checking a document written in XML (e Xtensible Markup Language) to confirm that it is both well-formed and also "valid" in that it follows a defined structure.