使用python minidom解析文档

Question

我有以下XML文档,我必须使用python的minidom解析:

<?xml version="1.0" encoding="UTF-8"?>

<root>
    <bash-function activated="True">
        <name>lsal</name>
        <description>List directory content (-al)</description>
        <code>ls -al</code>
    </bash-function>

    <bash-function activated="True">
        <name>lsl</name>
        <description>List directory content (-l)</description>
        <code>ls -l</code>
    </bash-function>
</root>

这是我试图解析的代码(基本部分):

from modules import BashFunction
from xml.dom.minidom import parse

class FuncDoc(object):
    def __init__(self, xml_file):
        self.active_func = []
        self.inactive_func = []
        try:
            self.dom = parse(xml_file)
        except Exception as inst:
            print type(inst)
            print inst.args
            print inst

不幸的是我遇到了一些错误.这是堆栈跟踪:

<class 'xml.parsers.expat.ExpatError'>
('no element found: line 1, column 0',)
no element found: line 1, column 0

作为一个蟒蛇初学者,请你指出问题的根源.

Answer 1

我想你是通过以下方式传递文件句柄:

>>> from xml.dom.minidom import parse
>>> xmldoc = open("xmltestfile.xml", "rU")
>>> x = FuncDoc(xmldoc)

如果我尝试解析同一个文档两次而不关闭它,我会得到同样的错误.试试这个 - 第二次解析后出现错误:

>>> xmldoc.close()
>>> xmldoc = open("xmltestfile.xml", "rU")
>>> xml1 = parse(xmldoc)
>>> xml2 = parse(xmldoc)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/xml/dom/minidom.py", line 1918, in parse
    return expatbuilder.parse(file)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/xml/dom/expatbuilder.py", line 928, in parse
    result = builder.parseFile(file)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/xml/dom/expatbuilder.py", line 211, in parseFile
    parser.Parse("", True)
xml.parsers.expat.ExpatError: no element found: line 1, column 0

首次解析后,已读取整个文件.然后,新的解析尝试接收0数据.我的猜测是文档被解析两次是你代码中的错误.但是,如果这是你想要做的,你可以重置它xmldoc.seek(0).