fix: OSS Python SDK hygiene batch, 9 small bug fixes (#6770)

tests/rerankers/test_reranker_fallback_topk.py

@@ -1,52 +1,9 @@
-"""Regression tests for the reranker fallback path honoring ``config.top_k``.
-
-When the underlying rerank call fails, the reranker falls back to returning the
-documents in their original order. That fallback must still respect the
-configured ``top_k`` limit, exactly like the success path does. The HuggingFace
-and SentenceTransformer rerankers already behave this way; these tests pin the
-same contract for the Cohere and ZeroEntropy rerankers.
-"""
-
-import sys
-from types import ModuleType
-from unittest.mock import MagicMock
-
-import pytest
+"""Regression tests pinning that the reranker fallback path still honors ``config.top_k``."""
 
 from mem0.configs.rerankers.cohere import CohereRerankerConfig
 from mem0.configs.rerankers.zero_entropy import ZeroEntropyRerankerConfig
 
 
-@pytest.fixture
-def mock_cohere(monkeypatch):
-    """Provide a fake ``cohere`` module so CohereReranker imports/constructs."""
-    fake_cohere = ModuleType("cohere")
-    fake_client = MagicMock()
-    fake_cohere.Client = MagicMock(return_value=fake_client)
-    monkeypatch.setitem(sys.modules, "cohere", fake_cohere)
-
-    import mem0.reranker.cohere_reranker as cohere_reranker
-
-    monkeypatch.setattr(cohere_reranker, "cohere", fake_cohere, raising=False)
-    monkeypatch.setattr(cohere_reranker, "COHERE_AVAILABLE", True, raising=False)
-    return cohere_reranker, fake_client
-
-
-@pytest.fixture
-def mock_zero_entropy(monkeypatch):
-    """Provide a fake ``zeroentropy`` module so ZeroEntropyReranker imports."""
-    fake_module = ModuleType("zeroentropy")
-    fake_client = MagicMock()
-    fake_module.ZeroEntropy = MagicMock(return_value=fake_client)
-    monkeypatch.setitem(sys.modules, "zeroentropy", fake_module)
-
-    import mem0.reranker.zero_entropy_reranker as zero_entropy_reranker
-
-    monkeypatch.setattr(zero_entropy_reranker, "ZeroEntropy", fake_module.ZeroEntropy, raising=False)
-    monkeypatch.setattr(zero_entropy_reranker, "ZERO_ENTROPY_AVAILABLE", True, raising=False)
-    return zero_entropy_reranker, fake_client
-
-
 def _docs(n):
     return [{"memory": f"doc{i}"} for i in range(n)]