Question

基本上，类似于System.Xml.XmlWriter - 流式XML Writer，它不会产生很大的内存开销。因此排除了xml.dom和xml.dom.minidom。建议？

Answer 1

我想你会发现xml.sax.saxutils中的XMLGenerator与你想要的最接近。

import time
from xml.sax.saxutils import XMLGenerator
from xml.sax.xmlreader import AttributesNSImpl

LOG_LEVELS = ['DEBUG', 'WARNING', 'ERROR']


class xml_logger:
    def __init__(self, output, encoding):
        """
        Set up a logger object, which takes SAX events and outputs
        an XML log file
        """
        logger = XMLGenerator(output, encoding)
        logger.startDocument()
        attrs = AttributesNSImpl({}, {})
        logger.startElementNS((None, u'log'), u'log', attrs)
        self._logger = logger
        self._output = output
        self._encoding = encoding
        return

    def write_entry(self, level, msg):
        """
        Write a log entry to the logger
        level - the level of the entry
        msg   - the text of the entry.  Must be a Unicode object
        """
        #Note: in a real application, I would use ISO 8601 for the date
        #asctime used here for simplicity
        now = time.asctime(time.localtime())
        attr_vals = {
            (None, u'date'): now,
            (None, u'level'): LOG_LEVELS[level],
            }
        attr_qnames = {
            (None, u'date'): u'date',
            (None, u'level'): u'level',
            }
        attrs = AttributesNSImpl(attr_vals, attr_qnames)
        self._logger.startElementNS((None, u'entry'), u'entry', attrs)
        self._logger.characters(msg)
        self._logger.endElementNS((None, u'entry'), u'entry')
        return

    def close(self):
        """
        Clean up the logger object
        """
        self._logger.endElementNS((None, u'log'), u'log')
        self._logger.endDocument()
        return

if __name__ == "__main__":
    #Test it out
    import sys
    xl = xml_logger(sys.stdout, 'utf-8')
    xl.write_entry(2, u"Vanilla log entry")
    xl.close()

您可能希望查看我在http://www.xml.com/pub/a/2003/03/12/py-xml.html得到的文章的其余部分。

Answer 2

我想我有你的毒药：

http://sourceforge.net/projects/xmlite

干杯

Answer 3

几年前，我使用4suite

中的MarkupWriter

General-purpose utility class for generating XML (may eventually be
expanded to produce more output types)

Sample usage:

from Ft.Xml import MarkupWriter
writer = MarkupWriter(indent=u"yes")
writer.startDocument()
writer.startElement(u'xsa')
writer.startElement(u'vendor')
#Element with simple text (#PCDATA) content
writer.simpleElement(u'name', content=u'Centigrade systems')
#Note writer.text(content) still works
writer.simpleElement(u'email', content=u"info@centigrade.bogus")
writer.endElement(u'vendor')
#Element with an attribute
writer.startElement(u'product', attributes={u'id': u"100\u00B0"})
#Note writer.attribute(name, value, namespace=None) still works
writer.simpleElement(u'name', content=u"100\u00B0 Server")
#XML fragment
writer.xmlFragment('<version>1.0</version><last-release>20030401</last-release>')
#Empty element
writer.simpleElement(u'changes')
writer.endElement(u'product')
writer.endElement(u'xsa')
writer.endDocument()

Note on the difference between 4Suite writers and printers
Writer  - module that exposes a broad public API for building output
          bit by bit
Printer - module that simply takes a DOM and creates output from it
          as a whole, within one API invokation

最近我听到很多关于lxml如何很棒的消息，但我没有第一手经验，而且我在使用gnosis时感到非常有趣。

Answer 4

lxml我的成绩总是很好。安装很麻烦，因为它主要是libxml2的包装器，但是lxml.etree树对象有一个.write()方法，它将类似文件的对象传输到。

from lxml.etree import XML

tree = XML('<root><a><b/></a></root>')
tree.write(your_file_object)

Answer 5

ElementTree的第二次投票（cElementTree是一个更快的C实现，比如cPickle vs pickle）。这里有一些简短的示例代码，您可以查看它以了解它是如何工作的：http://effbot.org/zone/element-index.htm （这是Fredrik Lundh，他首先编写了这个模块。它非常好用2.5 :-)编写标准库。

Answer 6

xml.etree.cElementTree ，自2.5以来包含在CPython的默认分发中。快速读取和写入XML。

从Python输出XML最容易的非内存密集型方法是什么？

6 个答案: