Dynamic Method Binding in Python

README.md

Dynamic Method Binding in Python

requirements.txt

pytest

test_bind_with_types_methodtype.py

import types as t

class User:
    def save(self):
        raise NotImplementedError()

class TestBinding:
    def test_bind_with_types_methodtype(self):
        def save(self, *args, **kwargs):
            calls.append((self, args, kwargs))
        calls = []
        u = User()

        # Replace the original method
        u.save = t.MethodType(save, u)
        # Call the replaced method
        u.save()
        # Assert the actual implementation was called
        assert calls == [(u, tuple(), {})]

test_with___get__.py

class User:
    def save(self):
        raise NotImplementedError()

class TestBinding:
    def test_bind_with_setattr(self):
        def save(self, *args, **kwargs):
            calls.append((self, args, kwargs))
        calls = []
        u = User()

        # Replace the method
        u.save = save.__get__(u, u.__class__)
        # Call the replaced method
        u.save()
        # Assert replacement is called
        assert calls == [(u, tuple(), {})]