如何在python中使用ElementTree输出XML文件？

Question

I'm slightly confused about writing an xml file using the xml ElementTree module. I tried to build the document: eg

a = ET.Element('a')
b = ET.SubElement(a, 'b')
c = ET.SubElement(a, 'c')
d = ET.SubElement(c, 'd')

How do I exactly take this, and write it to a file?

Answer 1

Create an instance of ElementTree class and call write() :

class xml.etree.ElementTree.ElementTree(element=None, file=None)

ElementTree wrapper class. This class represents an entire element hierarchy, and adds some extra support for serialization to and from standard XML .

element is the root element. The tree is initialized with the contents of the XML file if given.

tree = ET.ElementTree(a)
tree.write("output.xml")

Answer 2

You can write xml using ElementTree.write() function -

import xml.etree.ElementTree as ET
a = ET.Element('a')
b = ET.SubElement(a, 'b')
c = ET.SubElement(a, 'c')
d = ET.SubElement(c, 'd')
ET.ElementTree(a).write("test.xml")

This would write to file - test.xml -

<a><b /><c><d /></c></a>

---

To write xml with indents and elements on newline , you can use - xml.dom.minidom.toprettyxml . Example -

import xml.etree.ElementTree as ET
import xml.dom.minidom as md
a = ET.Element('a')
b = ET.SubElement(a, 'b')
c = ET.SubElement(a, 'c')
d = ET.SubElement(c, 'd')
xmlstr = ET.tostring(a).decode()
newxml = md.parse(xmlstr)
newxml = md.parseString(xmlstr)
with open('test.xml','w') as outfile:
    outfile.write(newxml.toprettyxml(indent='\t',newl='\n'))

Now, test.xml would look like -

<?xml version="1.0" ?>
<a>
    <b/>
    <c>
        <d/>
    </c>
</a>