playing with lazy class properties using jinja recursive templates

foo.py

from jinja2 import Template
from jinja2.runtime import Context


def merge_vars(obj):
    d = {}
    for o in reversed(obj.mro()):
        d.update(vars(o))
    return d

class TemplateProperty(Template):

    def __get__(self, obj, cls):
        class MyContext(Context):
            def resolve(self, key):
                v = super().resolve(key)
                if isinstance(v, (TemplateProperty,)):
                    return v.render(**merge_vars(cls))
                return v

        self.environment.context_class = MyContext
        return self.render(**merge_vars(cls))

    def __set__(self, obj, value):
        raise AttributeError()

class Base:
    first_name = 'Daniel'
    last_name = 'Hilst'
    full_name = TemplateProperty('{{first_name}} {{last_name}}') 
    reversed_full_name_cap = TemplateProperty('{{full_name[::-1].capitalize()}}')

class Child(Base):
    last_name = 'Selli'
    upper_name = TemplateProperty('{{full_name.upper()}}')

class Grandson(Child):
    lower_name = TemplateProperty('{{full_name.lower()}}')
    missing = TemplateProperty('{{undefined_property}}')

print(Base.full_name) # Daniel Hilst
print(Base.reversed_full_name_cap) # Tslih leinad
print(Child.full_name) # Daniel Selli
print(Child.upper_name) # DANIEL SELLI
print(Grandson.lower_name) # daniel selli
print(Grandson.missing)