使用 Python 从 XML 中读取/提取数据

Question

I am trying to read/extract data from XML with Python using xml.etree.ElementTree. Unfortunately, up to now, I didn't find how to do it. Most probably because I didn't understand how xml works.

The idea is to write the DocumentId number as a list

Here is my XML file:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<RegisterSearch TotalResults="4">
  <SearchResults>
    <Document DocumentId="1348828088501913376">
      <DocumentNumber>001</DocumentNumber>
    </Document>
    <Document DocumentId="1348828088501881434">
      <DocumentNumber>001</DocumentNumber>
    </Document>
    <Document DocumentId="1348828088539553420">
      <DocumentNumber>010</DocumentNumber>
    </Document>
    <Document DocumentId="1348828088539570694">
      <DocumentNumber>010</DocumentNumber>
    </Document>
  </SearchResults>
</RegisterSearch>

And here is my Python code:

#!/usr/bin/python2

import xml.etree.ElementTree as ET
tree = ET.parse('documents.xml')
root = tree.getroot()

for elem in root:
    if(elem.tag=='Document'):
        print elem.get('DocumentId')

This is what I try to achieve:

1348828088501913376
1348828088501881434
1348828088539553420
1348828088539570694

Actually, the code brings back nothing...

Thanks in advance for your suggestion.

Answer 1

Iterate over the tags you are interested in:

for elem in root.iter(tag='Document'):
    print(elem.get('DocumentId'))

Your original solution would work with

for elem in root.iter():
    ...

---

v3.8: https://docs.python.org/3/library/xml.etree.elementtree.html#finding-interesting-elements

v2.7: https://docs.python.org/2.7/library/xml.etree.elementtree.html#finding-interesting-elements