Is it necessary to subclass "object" when defining a new class in python3?

Question

It seems unnecessary to me.

But I still wondering why some sample codes (python3) still inherit this style.

For example (quoted from Django 2 by Example):

from django.contrib.auth.models import User

class EmailAuthBackend(object):
    ....

Can someone explain a bit?

Thanks!

Go through [this answer](https://stackoverflow.com/a/45062077/7832176). — Keyur Potdar, Apr 16 '20 at 11:22

score 2 · Accepted Answer · answered Apr 16 '20 at 11:22

It's not necessary. In Python 2 you had to do this to opt in to new-style classes; in Python 3, all classes are automatically "new-style" (old-style doesn't exist), so inheriting from object is equivalent to not inheriting from anything.

Likely the code you're seeing is legacy code that was directly adapted from older Python 2 code, or written by someone with Python 2 habits, and they never bothered to remove the explicit object base, since it's harmless to leave it in.

score 1 · Answer 2 · answered Apr 16 '20 at 11:23

1

No, now this is no longer necessary. I think this code was left for backward compatibility.

answered Apr 16 '20 at 11:23

SimfikDuke

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Is it necessary to subclass "object" when defining a new class in python3?

2 Answers2