How do convert a pandas dataframe to XML?

Is there a simple way to take a pandas/df table:

field_1 field_2 field_3 field_4
cat     15,263  2.52    00:03:00
dog     1,652   3.71    00:03:47
test     312    3.27    00:03:41
book     300    3.46    00:02:40

And convert it to XML along the lines of:

<item>
  <field name="field_1">cat</field>
  <field name="field_2">15263</field>
  <field name="filed_3">2.52</field>

...

<item>
      <field name="field_1">dog</field>

etc.

Solution 1:

You can create a function that creates the item node from a row in your DataFrame:

def func(row):
    xml = ['<item>']
    for field in row.index:
        xml.append('  <field name="{0}">{1}</field>'.format(field, row[field]))
    xml.append('</item>')
    return '\n'.join(xml)

And then apply the function along the axis=1.

>>> print '\n'.join(df.apply(func, axis=1))
<item>
  <field name="field_1">cat</field>
  <field name="field_2">15,263</field>
  <field name="field_3">2.52</field>
  <field name="field_4">00:03:00</field>
</item>
<item>
  <field name="field_1">dog</field>
  <field name="field_2">1,652</field>
  <field name="field_3">3.71</field>
  <field name="field_4">00:03:47</field>
</item>
...

Solution 2:

To expand on Viktor's excellent answer (and tweaking it slightly to work with duplicate columns), you could set this up as a to_xml DataFrame method:

def to_xml(df, filename=None, mode='w'):
    def row_to_xml(row):
        xml = ['<item>']
        for i, col_name in enumerate(row.index):
            xml.append('  <field name="{0}">{1}</field>'.format(col_name, row.iloc[i]))
        xml.append('</item>')
        return '\n'.join(xml)
    res = '\n'.join(df.apply(row_to_xml, axis=1))

    if filename is None:
        return res
    with open(filename, mode) as f:
        f.write(res)

pd.DataFrame.to_xml = to_xml

Then you can print the xml:

In [21]: print df.to_xml()
<item>
  <field name="field_1">cat</field>
  <field name="field_2">15,263</field>
  <field name="field_3">2.52</field>
  <field name="field_4">00:03:00</field>
</item>
<item>
...

or save it to a file:

In [22]: df.to_xml('foo.xml')

Obviously this example should be tweaked to fit your xml standard.

Solution 3:

You can use the xml.etree.ElementTree package to generate a read-friendly format in a very few lines of code.

root = etree.Element('data');

for i,row in dframe.iterrows():
    item = etree.SubElement(root, 'item', attrib=row.to_dict());

etree.dump(root);

This will create a XML Tree (under root), where each row will will be of type item, and have attributes for all columns. You can create a more nested tree with columns as well by creating a subelement for each field.

Then you can also read the xml file back in Python using the ElementTree package:

xml.etree.ElementTree.parse('xml_file.xml');

Solution 4:

As of v1.3, you can simply use:

df.to_xml()