Python xml ElementTree from a string source?
Question:
The ElementTree.parse reads from a file, how can I use this if I already have the XML data in a string?
Maybe I am missing something here, but there must be a way to use the ElementTree without writing out the string to a file and reading it again.
Answers:
If you’re using xml.etree.ElementTree.parse to parse from a file, then you can use xml.etree.ElementTree.fromstring to get the root Element of the document. Often you don’t actually need an ElementTree.
You need the xml.etree.ElementTree.fromstring(text)
from xml.etree.ElementTree import XML, fromstring
myxml = fromstring(text)
You can parse the text as a string, which creates an Element, and create an ElementTree using that Element.
import xml.etree.ElementTree as ET
tree = ET.ElementTree(ET.fromstring(xmlstring))
I just came across this issue and the documentation, while complete, is not very straightforward on the difference in usage between the parse() and fromstring() methods.
io.StringIO is another option for getting XML into xml.etree.ElementTree:
import io
f = io.StringIO(xmlstring)
tree = ET.parse(f)
root = tree.getroot()
Hovever, it does not affect the XML declaration one would assume to be in tree (although that’s needed for ElementTree.write()). See How to write XML declaration using xml.etree.ElementTree.
The ElementTree.parse reads from a file, how can I use this if I already have the XML data in a string?
Maybe I am missing something here, but there must be a way to use the ElementTree without writing out the string to a file and reading it again.
If you’re using xml.etree.ElementTree.parse to parse from a file, then you can use xml.etree.ElementTree.fromstring to get the root Element of the document. Often you don’t actually need an ElementTree.
You need the xml.etree.ElementTree.fromstring(text)
from xml.etree.ElementTree import XML, fromstring
myxml = fromstring(text)
You can parse the text as a string, which creates an Element, and create an ElementTree using that Element.
import xml.etree.ElementTree as ET
tree = ET.ElementTree(ET.fromstring(xmlstring))
I just came across this issue and the documentation, while complete, is not very straightforward on the difference in usage between the parse() and fromstring() methods.
io.StringIO is another option for getting XML into xml.etree.ElementTree:
import io
f = io.StringIO(xmlstring)
tree = ET.parse(f)
root = tree.getroot()
Hovever, it does not affect the XML declaration one would assume to be in tree (although that’s needed for ElementTree.write()). See How to write XML declaration using xml.etree.ElementTree.