Pass an object to a class, then make an object of it and pass again

[buran]

I had no intention to go into details about properties/setters, but maybe it's worth a bit of explaining

Let's say we have class Person. It has two attributes which we pass when instantiate it

class Person:
    def __init__(self, first_name, last_name):
        self.first_name = first_name
        self.last_name = last_name

person = Person('John', 'Doe')
print(person.first_name)
print(person.last_name)

What if we want a third attribute name that is the full name, i.e. <first_name> <last_name> - John Doe.
We can add a third attribute, just the same like the other two. However to have consistency we can do

class Person:
    def __init__(self, first_name, last_name):
        self.first_name = first_name
        self.last_name = last_name

    @property
    def name(self):
        return f'{self.first_name} {self.last_name}'

person = Person('John', 'Doe')
print(person.first_name)
print(person.last_name)
print(person.name)
person.name = 'Jack Ryan'

If you run the snippet you can see we are not able to change name (it raise error). To be able to change it, we can define setter for name. Again, for consistency we need to change also first_name and/or last_name when we change name, e.g.

class Person:
    def __init__(self, first_name, last_name):
        self.first_name = first_name
        self.last_name = last_name

    @property
    def name(self):
        return f'{self.first_name} {self.last_name}'

    @name.setter
    def name(self, value):
        self.first_name, *_, self.last_name = value.split(' ')

person = Person('John', 'Doe')
print(person.first_name)
print(person.last_name)
print(person.name)
person.name = 'Jack Ryan'
print(person.first_name)
print(person.last_name)
print(person.name)

Output:
John
Doe
John Doe
Jack
Ryan
Jack Ryan

This is just a basic example, in other cases you may need to use "private" variable, that is considered "for internal use" and it is designated by single underscore, e.g. _some_name. This is not really private variable like in other languages, just by convention "for internal use".