How to extend the Entry class?

[jasongabler]

I am trying to extend the Entry class so that I can have situation-specific versions of the class, adding additional class member variables and functions for woking with my organization's business logic. After spending a day working with this, it seems that it might be more difficult to accomplish than the worth of the desired benefit.

Firstly, Entry's are read-only, as told by __setattr__'s output. This got me to move onto the second idea of trying WritableEntry. However, WriteableEntry gets unhappy with adding new class attributes because itwants class attributes, with a few internally important exceptions, to follow the LDAP scheme for the Entry's objectClass. So if you try to use a class attribute that's not in the scheme attribute, __setattr__ complains that you "cannot add" attributes.

class User(Entry):
    def __init__(self, dn, cursor):
        super().__init__(dn, cursor)

or

class User(WritableEntry):
    ....

This is where I stopped trying to extend Entry.

I should also mention that I assumed it is required to extend Reader, otherwise there was ostensibly no way to tell Reader to return instances of my subclass of Entry rather than Entry itself. At first I extended Reader and set self.entry_class in the constructor. To my surprise, that did absolutely nothing and I was still getting back Entry's. Eventually, I tried setting reader.entry_class from the function that was calling Reader's constructor (so, after the Reader was fully created) , and only then would the Reader return my Entry subclass.

class UcsfReader(Reader):
    def __init__(self, connection, object_def, base, query='', components_in_and=True, sub_tree=True,
                 get_operational_attributes=False, attributes=None, controls=None, auxiliary_class=None,
                 entry_class=Entry):
        super().__init__(connection, object_def, base, query='', components_in_and=components_in_and,
                         sub_tree=sub_tree, get_operational_attributes=get_operational_attributes,
                         attributes=attributes, controls=controls, auxiliary_class=auxiliary_class)
        self.entry_class = entry_class

The only other alternative that I'm currently working with is to fake it: create a class with all my organization's business logic and then have an Ldap3 Entry as a member variable. If an attribute is not found in MyEntry, Python looks for it in Entry. I fear that this would only cause trouble own the road...

class MyEntry(Entry):
    def __init__(self, ldap3_entry):
        self.entry = ldap3_entry

    def __getattr__(self, attr):
        if attr not in self.__dict__:
            return getattr(self.entry, attr)
        return self.__getattr__(attr)