paxb 0.1.0

Python Architecture for XML Binding

Python Architecture for XML Binding

paxb is a library that provides an API for mapping between XML documents and Python objects.

paxb library implements the following functionality:

• Deserialize XML documents to Python objects

• Validate deserialized data

• Access and update Python object fields

• Serialize Python objects to XML documents

paxb provides an efficient way of mapping between an XML document and a Python object. Using paxb developers can write less boilerplate code emphasizing on application business logic.

As soon as paxb based on attrs library paxb and attrs API can be mixed together.

Installation

You can install paxb with pip:

$ pip install paxb

Requirements

• attrs

Quick start

user.xml:

<?xml version="1.0" encoding="utf-8"?>
<doc:envelope xmlns="http://www.test.org"
              xmlns:doc="http://www.test1.org">
    <doc:user name="Alexey" surname="Ivanov" age="26">

        <doc:birthdate year="1992" month="06" day="14"/>

        <doc:contacts>
            <doc:phone>[phone]</doc:phone>
            <doc:email>[e-mail]</doc:email>
            <doc:email>[e-mail]</doc:email>
        </doc:contacts>

        <doc:documents>
            <doc:passport series="3127" number="836815"/>
        </doc:documents>

        <data:occupations xmlns:data="http://www.test2.org">
            <data:occupation title="yandex">
                <data:address>Moscow</data:address>
                <data:employees>8854</data:employees>
            </data:occupation>
            <data:occupation title="skbkontur">
                <data:address>Yekaterinburg</data:address>
                <data:employees>7742</data:employees>
            </data:occupation>
        </data:occupations>

    </doc:user>
</doc:envelope>

main.py:

import re
from datetime import date
from pprint import pprint

import attr
import paxb as pb


@pb.model(name='occupation', ns='data', ns_map={'data': 'http://www.test2.org'})
class Occupation:
    title = pb.attr()
    address = pb.field()
    employees = pb.field(converter=int)


@pb.model(name='user', ns='doc', ns_map={'doc': 'http://www.test1.org'})
class User:
    name = pb.attr()
    surname = pb.attr()
    age = pb.attr(converter=int)

    birth_year = pb.wrap('birthdate', pb.attr('year', converter=int))
    birth_month = pb.wrap('birthdate', pb.attr('month', converter=int))
    birth_day = pb.wrap('birthdate', pb.attr('day', converter=int))

    @property
    def birthdate(self):
        return date(year=self.birth_year, month=self.birth_month, day=self.birth_day)

    @birthdate.setter
    def birthdate(self, value):
        self.birth_year = value.year
        self.birth_month = value.month
        self.birth_day = value.day

    phone = pb.wrap('contacts', pb.field())
    emails = pb.wrap('contacts', pb.as_list(pb.field(name='email')))

    passport_series = pb.wrap('documents/passport', pb.attr('series'))
    passport_number = pb.wrap('documents/passport', pb.attr('number'))

    occupations = pb.wrap(
        'occupations', pb.lst(pb.nested(Occupation)), ns='data', ns_map={'data': 'http://www.test2.org'}
    )

    citizenship = pb.field(default='RU')

    @phone.validator
    def check(self, attribute, value):
        if not re.match(r'\+\d{11,13}', value):
            raise ValueError("phone number is incorrect")


try:
    user = pb.from_xml(User, xml, envelope='doc:envelope', ns_map={'doc': 'http://www.test1.org'})
    user.birthdate = user.birthdate.replace(year=1993)
    pprint(attr.asdict(user))

except (pb.exc.DeserializationError, ValueError) as e:
    print(f"deserialization error: {e}")

output:

{
    'age': 26,
    'birth_day': 14,
    'birth_month': 6,
    'birth_year': 1993,
    'citizenship': 'RU',
    'emails': ['[e-mail]', '[e-mail]'],
    'name': 'Alexey',
    'occupations': [
        {
            'address': 'Moscow',
            'employees': 8854,
            'title': 'yandex'
        },
        {
            'address': 'Yekaterinburg',
            'employees': 7742,
            'title': 'skbkontur'
        }
    ],
    'passport_number': '836815',
    'passport_series': '3127',
    'phone': '[phone]',
    'surname': 'Ivanov'
}