retrieve previously logged experiment metadata (#11)

Author: justusschock

src/litlogger/__init__.py

@@ -26,7 +26,7 @@
 from litlogger.experiment import Experiment
 
 # Import SDK functions
-from litlogger.init import finish, init
+from litlogger.init import finish, get_metadata, init
 
 # Global variables
 experiment: Experiment | None = None
@@ -54,6 +54,7 @@
     "log_model_artifact",
     "get_model_artifact",
     "finalize",
+    "get_metadata",
 ]
 
 try:

src/litlogger/experiment.py

@@ -92,7 +92,6 @@ def __init__(
         self._finalized = False
         self.store_step = store_step
         self.store_created_at = store_created_at
-        self._metadata = metadata
 
         # Initialize printer and stats tracking
         self._printer = Printer(verbose=verbose)
@@ -201,6 +200,16 @@ def teamspace(self) -> "Teamspace":
         """
         return self._teamspace
 
+    @property
+    def metadata(self) -> Dict[str, str]:
+        """Get the metadata associated with this experiment from the metrics stream.
+
+        Returns:
+            Dict[str, str]: The metadata dictionary with key-value pairs from code-defined tags.
+        """
+        tags = getattr(self._metrics_store, "tags", None) or []
+        return {tag.name: tag.value for tag in tags if tag.from_code}
+
     def log_metrics(self, metrics: Dict[str, float], step: int | None = None, **kwargs: float) -> None:
         """Log metrics to the experiment with background uploading.
 
@@ -559,5 +568,5 @@ def print_url(self) -> None:
             teamspace=self._teamspace.name,
             url=self._url,
             version=self.version,
-            metadata=self._metadata,
+            metadata=self.metadata,
         )

src/litlogger/init.py

@@ -141,3 +141,20 @@ def finish(status: str | None = None) -> None:
         raise RuntimeError("You must call litlogger.init() before litlogger.finish()")
 
     litlogger.experiment.finalize(status)
+
+
+def get_metadata() -> Dict[str, str]:
+    """Get the metadata associated with the current experiment.
+
+    Returns:
+        Dict[str, str]: The metadata dictionary with key-value pairs from the metrics stream.
+
+    Raises:
+        RuntimeError: If litlogger.init() has not been called.
+    """
+    import litlogger
+
+    if litlogger.experiment is None:
+        raise RuntimeError("You must call litlogger.init() before litlogger.get_metadata()")
+
+    return litlogger.experiment.metadata

tests/integrations/test_standalone.py

@@ -358,6 +358,9 @@ def test_error_handling_before_init():
     with pytest.raises(RuntimeError, match="You must call litlogger.init\\(\\)"):
         litlogger.finalize()
 
+    with pytest.raises(RuntimeError, match="You must call litlogger.init\\(\\)"):
+        litlogger.get_metadata()
+
 
 @pytest.mark.cloud()
 def test_multiple_experiments_in_sequence():
@@ -498,6 +501,131 @@ def test_metadata_and_tags():
     )
 
 
+@pytest.mark.cloud()
+def test_get_metadata():
+    """Test get_metadata() function and experiment.metadata property."""
+    experiment_name = f"meta_test-{uuid.uuid4().hex}"
+    metadata = {
+        "model": "GPT-2",
+        "dataset": "WikiText",
+        "learning_rate": "0.0001",
+        "batch_size": "16",
+    }
+
+    exp = litlogger.init(
+        name=experiment_name,
+        teamspace="oss-litlogger",
+        metadata=metadata,
+    )
+
+    # Test experiment.metadata property returns the metadata from the metrics stream
+    retrieved_metadata = exp.metadata
+    assert isinstance(retrieved_metadata, dict)
+    for key, value in metadata.items():
+        assert key in retrieved_metadata, f"Expected key '{key}' in metadata"
+        assert (
+            retrieved_metadata[key] == value
+        ), f"Expected metadata['{key}'] == '{value}', got '{retrieved_metadata[key]}'"
+
+    # Test litlogger.get_metadata() returns the same metadata
+    global_metadata = litlogger.get_metadata()
+    assert isinstance(global_metadata, dict)
+    for key, value in metadata.items():
+        assert key in global_metadata, f"Expected key '{key}' in global metadata"
+        assert global_metadata[key] == value
+
+    # Verify both return the same data
+    assert retrieved_metadata == global_metadata
+
+    litlogger.finalize()
+
+    # Cleanup
+    project_id = exp._teamspace.id
+    stream_id = exp._metrics_store.id
+
+    client = LitRestClient()
+    client.lit_logger_service_delete_metrics_stream(
+        project_id=project_id,
+        body=LitLoggerServiceDeleteMetricsStreamBody(ids=[stream_id]),
+    )
+
+
+@pytest.mark.cloud()
+def test_get_metadata_empty():
+    """Test get_metadata() when no metadata is provided."""
+    experiment_name = f"meta_empty_test-{uuid.uuid4().hex}"
+
+    exp = litlogger.init(
+        name=experiment_name,
+        teamspace="oss-litlogger",
+    )
+
+    # Test that metadata is empty dict when none provided
+    retrieved_metadata = exp.metadata
+    assert isinstance(retrieved_metadata, dict)
+    assert len(retrieved_metadata) == 0
+
+    # Test litlogger.get_metadata() also returns empty dict
+    global_metadata = litlogger.get_metadata()
+    assert isinstance(global_metadata, dict)
+    assert len(global_metadata) == 0
+
+    litlogger.finalize()
+
+    # Cleanup
+    project_id = exp._teamspace.id
+    stream_id = exp._metrics_store.id
+
+    client = LitRestClient()
+    client.lit_logger_service_delete_metrics_stream(
+        project_id=project_id,
+        body=LitLoggerServiceDeleteMetricsStreamBody(ids=[stream_id]),
+    )
+
+
+@pytest.mark.cloud()
+def test_get_metadata_direct_experiment():
+    """Test experiment.metadata property when using Experiment class directly."""
+    from datetime import datetime, timezone
+
+    experiment_name = f"meta_direct-{uuid.uuid4().hex}"
+    timestamp = datetime.now(timezone.utc).isoformat(timespec="milliseconds")
+    version_str = timestamp.replace("+00:00", "Z")
+
+    metadata = {
+        "framework": "PyTorch",
+        "version": "2.0",
+    }
+
+    with tempfile.TemporaryDirectory() as tmpdir:
+        exp = Experiment(
+            name=experiment_name,
+            version=version_str,
+            teamspace="oss-litlogger",
+            log_dir=tmpdir,
+            metadata=metadata,
+        )
+
+        # Test experiment.metadata property
+        retrieved_metadata = exp.metadata
+        assert isinstance(retrieved_metadata, dict)
+        for key, value in metadata.items():
+            assert key in retrieved_metadata
+            assert retrieved_metadata[key] == value
+
+        exp.finalize()
+
+        # Cleanup
+        project_id = exp._teamspace.id
+        stream_id = exp._metrics_store.id
+
+        client = LitRestClient()
+        client.lit_logger_service_delete_metrics_stream(
+            project_id=project_id,
+            body=LitLoggerServiceDeleteMetricsStreamBody(ids=[stream_id]),
+        )
+
+
 @pytest.mark.cloud()
 def test_custom_colors():
     """Test experiments with custom colors."""