Unable get list of subelements in proper order.

[vkouts]

I have xml document:

xml_text = '''<Periods>
    <Year>01.01.2023 0:00:00</Year>
    <Date_from>18.02.2023 0:00:00</Date_from>
    <Year>01.01.2023 0:00:00</Year>
    <Date_from>30.05.2023 0:00:00</Date_from>
    <Year>01.01.2023 0:00:00</Year>
    <Date_from>06.04.2023 0:00:00</Date_from>
    <Year>01.01.2023 0:00:00</Year>
    <Date_from>28.02.2023 0:00:00</Date_from>
    <Year>01.01.2023 0:00:00</Year>
    <Date_from>19.06.2023 0:00:00</Date_from>
    <Year>01.01.2023 0:00:00</Year>
    <Date_from>07.06.2023 0:00:00</Date_from>
</Periods>'''

and following code:

import pprint
from typing import List

from pydantic_xml import BaseXmlModel, element
from pydantic_xml.element.element import SearchMode

class Periods(BaseXmlModel, tag='Periods', search_mode=SearchMode.UNORDERED):
    year: List[str] = element(tag='Year', default_factory=list)
    date_from: List[str] = element(tag='Date_from', default_factory=list)

data = Periods.from_xml(xml_text)
pprint.pprint(data.date_from)

With search mode UNORDERED I getting list with wrong ordering:

 '28.02.2023 0:00:00',
 '18.02.2023 0:00:00',
 '19.06.2023 0:00:00',
 '06.04.2023 0:00:00',
 '07.06.2023 0:00:00']```

 Search modes **ORDERING** and **STRICT** returns only one element: 
 ```['07.06.2023 0:00:00']
 ['18.02.2023 0:00:00']```
 respectively. Trying to get list with needed ordering have no success.

[dapper91]

@vkouts Hi

UNORDERED mode doesn't keep fields order by design so they are serialized in an arbitrary order.

Starting from version 2.5.0 it is possible to group adjacent elements in tuples. See the documentation.

In your case the model may be described like this:

import pprint
from typing import List, Tuple

from pydantic_xml import RootXmlModel

class Year(RootXmlModel[str], tag='Year'): pass
class DateFrom(RootXmlModel[str], tag='Date_from'): pass

class Periods(RootXmlModel, tag='Periods'):
    root: List[Tuple[Year, DateFrom]] = []

xml_text = '''<Periods>
    <Year>01.01.2023 0:00:00</Year>
    <Date_from>18.02.2023 0:00:00</Date_from>
    <Year>01.01.2023 0:00:00</Year>
    <Date_from>30.05.2023 0:00:00</Date_from>
    <Year>01.01.2023 0:00:00</Year>
    <Date_from>06.04.2023 0:00:00</Date_from>
    <Year>01.01.2023 0:00:00</Year>
    <Date_from>28.02.2023 0:00:00</Date_from>
    <Year>01.01.2023 0:00:00</Year>
    <Date_from>19.06.2023 0:00:00</Date_from>
    <Year>01.01.2023 0:00:00</Year>
    <Date_from>07.06.2023 0:00:00</Date_from>
</Periods>'''

data = Periods.from_xml(xml_text)
pprint.pprint(data)