python - 如何设置 pandas 的 read_xml 的 `xpath`？

Question

我想从其部分的xml 文件Component中解析数据：

<Component>
  <UnderlyingSecurityID>300001</UnderlyingSecurityID>
  <UnderlyingSecurityIDSource>102</UnderlyingSecurityIDSource>
  <UnderlyingSymbol>特锐德&lt;/UnderlyingSymbol>
  <ComponentShare>300.00</ComponentShare>
  <SubstituteFlag>1</SubstituteFlag>
  <PremiumRatio>0.25000</PremiumRatio>
  <CreationCashSubstitute>0.0000</CreationCashSubstitute>
  <RedemptionCashSubstitute>0.0000</RedemptionCashSubstitute>
</Component>
<Component>
  <UnderlyingSecurityID>300003</UnderlyingSecurityID>
  <UnderlyingSecurityIDSource>102</UnderlyingSecurityIDSource>
  <UnderlyingSymbol>乐普医疗</UnderlyingSymbol>
  <ComponentShare>600.00</ComponentShare>
  <SubstituteFlag>1</SubstituteFlag>
  <PremiumRatio>0.25000</PremiumRatio>
  <CreationCashSubstitute>0.0000</CreationCashSubstitute>
  <RedemptionCashSubstitute>0.0000</RedemptionCashSubstitute>
</Component>

我已经安装了最新版本的 lxml 和 pandas，尝试了以下代码但没有运气。

Python 3.9.4 (tags/v3.9.4:1f2e308, Apr  6 2021, 13:40:21) [MSC v.1928 64 bit (AMD64)]
Type 'copyright', 'credits' or 'license' for more information
IPython 7.25.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: import pandas as pd

In [2]: pd.__version__
Out[2]: '1.3.0'

In [3]: xml = pd.read_xml('https://www.huaan.com.cn/etf/159949/etffiledownload.jsp?etffilename=pcf_159949_20210707.xml', xpath='//component')
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-3-67d228028cc9> in <module>
----> 1 xml = pd.read_xml('https://www.huaan.com.cn/etf/159949/etffiledownload.jsp?etffilename=pcf_159949_20210707.xml', xpath='//component')

...
    501         if elems == []:
--> 502             raise ValueError(msg)
    503 
    504         if elems != [] and attrs == [] and children == []:

ValueError: xpath does not return any nodes. Be sure row level nodes are in xpath. If document uses namespaces denoted with xmlns, be sure to define namespaces and use them in xpath.

In [4]: xml = pd.read_xml('https://www.huaan.com.cn/etf/159949/etffiledownload.jsp?etffilename=pcf_159949_20210707.xml', xpath='//component', namespaces={'com': 'http://ts.szse.cn/Fund'})
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-4-52fbe542dadb> in <module>
----> 1 xml = pd.read_xml('https://www.huaan.com.cn/etf/159949/etffiledownload.jsp?etffilename=pcf_159949_20210707.xml', xpath='//component', namespaces={'com': 'http://ts.szse.cn/Fund'})

...
    501         if elems == []:
--> 502             raise ValueError(msg)
    503 
    504         if elems != [] and attrs == [] and children == []:

ValueError: xpath does not return any nodes. Be sure row level nodes are in xpath. If document uses namespaces denoted with xmlns, be sure to define namespaces and use them in xpath.

我也直接尝试过lxml，似乎可行：

In [5]: from lxml import etree
In [6]: import requests
In [7]: content = requests.get('https://www.huaan.com.cn/etf/159949/etffiledownload.jsp?etffilename=pcf_159949_20210707.xml').content

In [8]: html = etree.HTML(content)
In [9]: html.xpath('//component')
Out[9]: 
[<Element component at 0x1d493cb23c0>,
 <Element component at 0x1d493cb2340>,
 <Element component at 0x1d493cb2240>,
 <Element component at 0x1d493cb22c0>,
 <Element component at 0x1d493cb2140>,
 <Element component at 0x1d493cb2040>,
 <Element component at 0x1d493cb2c40>,
 <Element component at 0x1d493cb61c0>,
 <Element component at 0x1d493cb63c0>,
 <Element component at 0x1d493cb2200>,
 ...

我不知道为什么read_xml不起作用。任何帮助，将不胜感激！

标签： pythonpandasxml