How to write XML declaration using xml.etree.ElementTree

Question

I am generating an XML document in Python using an ElementTree, but the tostring function doesn\'t include an XML declaration when converting to plaintext.

Answer 1

Including 'standalone' in the declaration

I didn't found any alternative for adding the standalone argument in the documentation so I adapted the ET.tosting function to take it as an argument.

from xml.etree import ElementTree as ET

# Sample
document = ET.Element('outer')
node = ET.SubElement(document, 'inner')
et = ET.ElementTree(document)

 # Function that you need   
 def tostring(element, declaration, encoding=None, method=None,):
     class dummy:
         pass
     data = []
     data.append(declaration+"\n")
     file = dummy()
     file.write = data.append
     ET.ElementTree(element).write(file, encoding, method=method)
     return "".join(data)
# Working example
xdec = """"""    
xml = tostring(document, encoding='utf-8', declaration=xdec)