object to string in Python

You can use __repr__ instead of __str__, which works recursively, although that is not a good idea most of the times (look at this answer for more details). Nevertheless, this works for me:

def __repr__(self):
    return str(self.__dict__)

You can try using repr instead of str.

I got the below output for print(t1), when using def repr(self): instead of str.

{'attr1': 'bean 1', 'attr2': [{'attr1': 'bean 1.1', 'attr2': 'same'}, {'attr1': 'bean 1.2', 'attr2': 42}]}

Let me know if this solves your problem. Attaching image for reference.

Regards, Vinith