在python中解析xml文件 - 找不到元素

Question

我是一个蟒蛇初学者。

我希望能够在xml工作表中选择某些元素的值。以下是我的xml表格：

  <TempFolder>D:\Mooniology\DiSecTemp\160708_M02091_0202_000000000-APC99</TempFolder>
  <AnalysisFolder>D:\Mooniology\MiSeqAnalysis\160708_M0209831_0202_000000000-APC99</AnalysisFolder>
  <RunStartDate>160708</RunStartDate>
  <MostRecentWashType>PostRun</MostRecentWashType>
  <RecipeFolder>D:\Mooniology\MiSeq Control Software\CustomRecipe</RecipeFolder>
  <ILMNOnlyRecipeFolder>C:\Mooniology\MiSeq Control Software\Recipe</ILMNOnlyRecipeFolder>
  <SampleSheetName>20160708 ALK Amplicon NGS cDNA synthesis kit comparison</SampleSheetName>
  <SampleSheetFolder>Q:\GNO MiSeq\Jaya</SampleSheetFolder>
  <ManifestFolder>Q:\GNO MiSeq</ManifestFolder>
  <OutputFolder>\\rpbns4-lab\vol10\RMSdisect\160708_M02091_0202_000000000-APC99</OutputFolder>
  <FocusMethod>AutoFocus</FocusMethod>
  <SurfaceToScan>Both</SurfaceToScan>
  <SaveFocusImages>true</SaveFocusImages>
  <SaveScanImages>true</SaveScanImages>

通过“选择值”，假设我想要名为TempFolder的元素的值。我希望脚本吐出D:\Mooniology\DiSecTemp\160708_M02091_0202_000000000-APC99下面是我用来尝试扫描它的代码：

#!/usr/bin/python2.7

import xml.etree.ElementTree as ET
tree = ET.parse('online.xml')
root = tree.getroot()
for child in root:
    print(child.tag, child.attrib)

每次我运行此代码，无论我如何修改它（从研究谷歌），最终结果始终是以下错误：

Traceback (most recent call last):
  File "./mindo.py", line 5, in <module>
    tree = ET.parse('online.xml')
  File "/usr/lib64/python2.7/xml/etree/ElementTree.py", line 1182, in parse
    tree.parse(source, parser)
  File "/usr/lib64/python2.7/xml/etree/ElementTree.py", line 657, in parse
    self._root = parser.close()
  File "/usr/lib64/python2.7/xml/etree/ElementTree.py", line 1654, in close
    self._raiseerror(v)
  File "/usr/lib64/python2.7/xml/etree/ElementTree.py", line 1506, in _raiseerror
    raise err
xml.etree.ElementTree.ParseError: no element found: line 75, column 0

我怀疑问题可能是我正在使用的xml文件。但是因为我是python的新手，所以我必须假设我的代码。

Answer 1

这是因为XML格式不正确，因此无法解析：

In [4]: tree = ET.parse('online.xml')
   ...: 
  File "<string>", line unknown
ParseError: junk after document element: line 2, column 2

xml需要有根元素，即：

  <params>
    <TempFolder>D:\Mooniology\DiSecTemp\160708_M02091_0202_000000000-APC99</TempFolder>
    <AnalysisFolder>D:\Mooniology\MiSeqAnalysis\160708_M0209831_0202_000000000-APC99</AnalysisFolder>
    <RunStartDate>160708</RunStartDate>
    <MostRecentWashType>PostRun</MostRecentWashType>
    ...
    ...
    ...
  </params>