CODEWITHSUNDEEP
pythonregexxml
Yves
Yves

Reputation: 35

Issues with python 3.x multiline regex?

I am very new to python and started coding with it a few weeks ago. Since now I was able to resolv any issues with researching and reading. But this issue gives me now headaches since several hours and I can't seam to find the correct solution.

I created a sample xml (test_file.xml) on my hard drive in the folder where also my read_xml.py file is located.

Content of read_xml.py (before)

import re

with open('test_file.xml') as xml_source:
  data = xml_source.read()
  xml_result = re.compile(r'<title>(.+?)</title>')
  mo = xml_result.search(data)
  print(mo.group(1))

gives me back TinkerTry which it should.

But if I go further like this

Content of read_xml.py (now):

import re

with open('test_file.xml') as xml_source:
  data = xml_source.read()
  xml_result = re.compile(r'<title>(.+?)</title>\n<link href="(.+?)"/>', re.MULTILINE)
  mo = xml_result.search(data)
  print(mo.group(1))

it does not seam to find / match anything anymore...

Upvotes: 0

Views: 52

Answers (1)

Jan
Jan

Reputation: 43169

In short: don't. If you're in the state of learning Python (or any other language, for that matter), trying to analyze XML nodes with regular expression is usually considered an anti-pattern. Instead, use a parser (that's what they were made for).

For your specific example this might come down to:

from lxml import etree
tree = etree.parse('test.xml')
root = tree.getroot()

for title in root.xpath("//item/title"):
    print(title.text)

And yields

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You see, this makes for cleaner and better to understand code. You might need to install lxml via pip install lxml first.
Note: there was an error in your XML file which I needed to correct for this to work (the link tag was opened but never closed).

Upvotes: 1

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