xml.sax.xmlreader — 用于 XML 剖析器的接口

源代码： Lib/xml/sax/xmlreader.py

SAX parsers implement the XMLReader interface. They are implemented in a Python module, which must provide a function create_parser() . This function is invoked by xml.sax.make_parser() with no arguments to create a new parser object.

class xml.sax.xmlreader. XMLReader

Base class which can be inherited by SAX parsers.

class xml.sax.xmlreader. IncrementalParser

In some cases, it is desirable not to parse an input source at once, but to feed chunks of the document as they get available. Note that the reader will normally not read the entire file, but read it in chunks as well; still parse() won’t return until the entire document is processed. So these interfaces should be used if the blocking behaviour of parse() is not desirable.

When the parser is instantiated it is ready to begin accepting data from the feed method immediately. After parsing has been finished with a call to close the reset method must be called to make the parser ready to accept new data, either from feed or using the parse method.

Note that these methods must not be called during parsing, that is, after parse has been called and before it returns.

By default, the class also implements the parse method of the XMLReader interface using the feed, close and reset methods of the IncrementalParser interface as a convenience to SAX 2.0 driver writers.

class xml.sax.xmlreader. Locator

Interface for associating a SAX event with a document location. A locator object will return valid results only during calls to DocumentHandler methods; at any other time, the results are unpredictable. If information is not available, methods may return None .

class xml.sax.xmlreader. InputSource ( system_id = None )

Encapsulation of the information needed by the XMLReader to read entities.

This class may include information about the public identifier, system identifier, byte stream (possibly with character encoding information) and/or the character stream of an entity.

Applications will create objects of this class for use in the XMLReader.parse() method and for returning from EntityResolver.resolveEntity.

An InputSource belongs to the application, the XMLReader is not allowed to modify InputSource objects passed to it from the application, although it may make copies and modify those.

class xml.sax.xmlreader. AttributesImpl ( attrs )

This is an implementation of the Attributes interface (see section The Attributes Interface ). This is a dictionary-like object which represents the element attributes in a startElement() call. In addition to the most useful dictionary operations, it supports a number of other methods as described by the interface. Objects of this class should be instantiated by readers; attrs must be a dictionary-like object containing a mapping from attribute names to attribute values.

class xml.sax.xmlreader. AttributesNSImpl ( attrs , qnames )

Namespace-aware variant of AttributesImpl , which will be passed to startElementNS() . It is derived from AttributesImpl , but understands attribute names as two-tuples of namespaceURI and localname . In addition, it provides a number of methods expecting qualified names as they appear in the original document. This class implements the AttributesNS interface (see section The AttributesNS Interface ).

XMLReader 对象

The XMLReader interface supports the following methods:

XMLReader. parse ( source )

Process an input source, producing SAX events. The source object can be a system identifier (a string identifying the input source – typically a file name or a URL), a pathlib.Path or 像路径 object, or an InputSource object. When parse() returns, the input is completely processed, and the parser object can be discarded or reset.

3.5 版改变： Added support of character streams.

3.8 版改变： Added support of path-like objects.