使用正则表达式修改XML

Question

I have to replace some 'file names' from within an XML with the full path for those files. All the files are in the same directory which simplifies things somewhat. I was trying to use BeautifulSoup4 but there was a bug that kept breaking crashing python so I'm trying to do the same thing with regex's.

The copasiML variable contains an XML as a string.

My code:

    copasiML=IA.read_copasiML_as_string(copasi_file)
    data_file_names=re.findall('<Parameter name="File Name" type="file" value="(.*)"/>',copasiML)
    for i in data_file_names:
        copasiML2=re.sub('<Parameter name="File Name" type="file" value="'+i+'"/>','<Parameter name="File Name" type="file" value="'+os.path.join(os.getcwd()+i)+'"/>',copasiML)
        os.remove(copasi_file)
        with open(copasi_file,'w') as f:
            f.write(str(copasiML2))

As it stands, my code runs but doesn't actually do anything. Would anybody happen to know how to fix my code?

Many thanks

Answer 1

Every time you try to parse HTML/XML with Regular Expressions, you make baby Jesus cry.

I BeautifulSoup doesn't work for you, I suggest XPath as illustrated in python lxml - modify attributes .

Fun (but instructive) readings:

• RegEx match open tags except XHTML self-contained tags
• Using regular expressions to parse HTML: why not?
• Why it's not possible to use regex to parse HTML/XML: a formal explanation in layman's terms
• https://news.ycombinator.com/item?id=2741780