Question

We have an XML document that has a tag we wish to alter:

...<version>1.0</version>...

It’s buried deep in the XML file, but we’re successfully able to use Beautiful Soup to replace its contents with a command-line parameter.

The problem is that after modifying the tree, we need to write back to the file we read it from. But, we want to maintain the original formatting of the document. When I use:

fileForWriting = open(myXmlFile, 'w')
fileForWriting.write(soup.prettify())

The prettify() call breaks the formatting, and I end up with:

<version>
 1.0
</version>

Is there any way to maintain the original formatting of the XML document, while replacing that single tag text?

Note: Using simply:

fileForWriting.write(str(soup))

Keeps the text and tags on the same line, but eliminates the indents and extra newlines that had been human-added for readability. Close, but no cigar.

By request, the entire script:

from BeautifulSoup import BeautifulSoup as bs

import sys

xmlFile = sys.argv[1:][0]
version = sys.argv[1:][1]

fileForReading = open(xmlFile, 'r')
xmlString = fileForReading.read()
fileForReading.close()

soup = bs(xmlString)

soup.findAll('version')[1].contents[0].replaceWith(version)

fileForWriting = open(xmlFile, 'w')
fileForWriting.write(str(soup))
fileForWriting.close()

The script is then run using:

python myscript.py someFile.xml 1.2

Answer 1

And if you use xml.elementtree, the tree.write(file) method replaces the CRLF by LF only, which also creates issues when trying to import the XML file into i.e. PyXB.

The solution I found is to use ElementTree just to find what I have to replace. Then I do source_XML = 'new value'.join(source_XML.split('what you need to replace)) Finally a file.write(source_XML)

it’s not nice, but it solves the issue. However, I do not mind about the indentations, so on this I can’t really say. I would only use pprint.pprint() whenever I need to print it.