xmltodict with force_list argument returns a list with None element for empty XML list

Question

I'm parsing XML with xmltodict with force_list=('xml_tag') in order to get list for single elements in XML list. And it works! However, in case when xml_tag has no child it returns a [None](list with single None object). How to prevent it?

XML

<Something>
    <Guitar>
        <name>Walden</name>
        <strings>5</strings>
    </Guitar>
    <Pokemons>
    </Pokemons>
</Something>

PYTHON

res = xmltodict.parse(xml, force_list=('Pokemons',))

res = res['Something']['Guitar']['Pokemons']

pprint(res)

>>> [None]

Any suggestions?

[UPDATE]

Sorry, I'm not clarifying what I want. I want to get empty list as result not list with None element

Answer 1

You can pass a postprocessing function to xmltodict, which allows you to modify the dict values.
But postprocecssing needs to return a key and a value:

import xmltodict
import json


def postprocessor(path, key, value):
    if key == 'Pokemons' and not value:
        return key, []
    return key, value

xml = """<Something>
    <Guitar>
        <name>Walden</name>
        <strings>5</strings>
    </Guitar>
    <Pokemons>
    </Pokemons>
</Something>"""


res = xmltodict.parse(xml, postprocessor=postprocessor)
print(json.dumps(res, indent=2, sort_keys=True))

Output:

{
  "Something": {
    "Guitar": {
      "name": "Walden",
      "strings": "5"
    },
    "Pokemons": []
  }
}