Add save_artifact method to _Step (#871)

* Add `save_artifact` method

* Upload pipeline generated artifacts

* Fix log file was being saved in different cache

* Update `save_to_disk` to also save artifacts

* Render artifacts in card

* Update unit tests

* Add missing unit tests

* Update src/distilabel/distiset.py

Co-authored-by: Agus <agustin@argilla.io>

* Add section about saving artifacts

* Add correct `edit_uri`

---------

Co-authored-by: Agus <agustin@argilla.io>

docs/sections/how_to_guides/advanced/saving_step_generated_artifacts.md

@@ -0,0 +1,123 @@
+# Saving step generated artifacts
+
+Some `Step`s might need to produce an auxiliary artifact that is not a result of the computation, but is needed for the computation. For example, the [`FaissNearestNeighbour`](/distilabel/components-gallery/steps/faissnearestneighbour/) needs to create a Faiss index to compute the output of the step which are the top `k` nearest neighbours for each input. Generating the Faiss index takes time and it could potentially be reused outside of the `distilabel` pipeline, so it would be a shame not saving it.
+
+For this reason, `Step`s have a method called `save_artifact` that allows saving artifacts that will be included along the outputs of the pipeline in the generated [`Distiset`][distilabel.distiset.Distiset]. The generated artifacts will be uploaded and saved when using `Distiset.push_to_hub` or `Distiset.save_to_disk` respectively. Let's see how to use it with a simple example.
+
+```python
+from typing import List, TYPE_CHECKING
+from distilabel.steps import GlobalStep, StepInput, StepOutput
+import matplotlib.pyplot as plt
+
+if TYPE_CHECKING:
+    from distilabel.steps import StepOutput
+
+
+class CountTextCharacters(GlobalStep):
+    @property
+    def inputs(self) -> List[str]:
+        return ["text"]
+
+    @property
+    def outputs(self) -> List[str]:
+        return ["text_character_count"]
+
+    def process(self, inputs: StepInput) -> "StepOutput":  # type: ignore
+        character_counts = []
+
+        for input in inputs:
+            text_character_count = len(input["text"])
+            input["text_character_count"] = text_character_count
+            character_counts.append(text_character_count)
+
+        # Generate plot with the distribution of text character counts
+        plt.figure(figsize=(10, 6))
+        plt.hist(character_counts, bins=30, edgecolor="black")
+        plt.title("Distribution of Text Character Counts")
+        plt.xlabel("Character Count")
+        plt.ylabel("Frequency")
+
+        # Save the plot as an artifact of the step
+        self.save_artifact(
+            name="text_character_count_distribution",
+            write_function=lambda path: plt.savefig(path / "figure.png"),
+            metadata={"type": "image", "library": "matplotlib"},
+        )
+
+        plt.close()
+
+        yield inputs
+```
+
+As it can be seen in the example above, we have created a simple step that counts the number of characters in each input text and generates a histogram with the distribution of the character counts. We save the histogram as an artifact of the step using the `save_artifact` method. The method takes three arguments:
+
+- `name`: The name we want to give to the artifact.
+- `write_function`: A function that writes the artifact to the desired path. The function will receive a `path` argument which is a `pathlib.Path` object pointing to the directory where the artifact should be saved.
+- `metadata`: A dictionary with metadata about the artifact. This metadata will be saved along with the artifact.
+
+Let's execute the step with a simple pipeline and push the resulting `Distiset` to the Hugging Face Hub:
+
+??? "Example full code"
+
+    ```python
+    from typing import TYPE_CHECKING, List
+
+    import matplotlib.pyplot as plt
+    from datasets import load_dataset
+    from distilabel.pipeline import Pipeline
+    from distilabel.steps import GlobalStep, StepInput, StepOutput
+
+    if TYPE_CHECKING:
+        from distilabel.steps import StepOutput
+
+
+    class CountTextCharacters(GlobalStep):
+        @property
+        def inputs(self) -> List[str]:
+            return ["text"]
+
+        @property
+        def outputs(self) -> List[str]:
+            return ["text_character_count"]
+
+        def process(self, inputs: StepInput) -> "StepOutput":  # type: ignore
+            character_counts = []
+
+            for input in inputs:
+                text_character_count = len(input["text"])
+                input["text_character_count"] = text_character_count
+                character_counts.append(text_character_count)
+
+            # Generate plot with the distribution of text character counts
+            plt.figure(figsize=(10, 6))
+            plt.hist(character_counts, bins=30, edgecolor="black")
+            plt.title("Distribution of Text Character Counts")
+            plt.xlabel("Character Count")
+            plt.ylabel("Frequency")
+
+            # Save the plot as an artifact of the step
+            self.save_artifact(
+                name="text_character_count_distribution",
+                write_function=lambda path: plt.savefig(path / "figure.png"),
+                metadata={"type": "image", "library": "matplotlib"},
+            )
+
+            plt.close()
+
+            yield inputs
+
+
+    with Pipeline() as pipeline:
+        count_text_characters = CountTextCharacters()
+
+    if __name__ == "__main__":
+        distiset = pipeline.run(
+            dataset=load_dataset(
+                "HuggingFaceH4/instruction-dataset", split="test"
+            ).rename_column("prompt", "text"),
+        )
+
+        distiset.push_to_hub("distilabel-internal-testing/distilabel-artifacts-example")
+    ```
+
+The generated [distilabel-internal-testing/distilabel-artifacts-example](https://huggingface.co/datasets/distilabel-internal-testing/distilabel-artifacts-example) dataset repository has a section in its card [describing the artifacts generated by the pipeline](https://huggingface.co/datasets/distilabel-internal-testing/distilabel-artifacts-example#artifacts) and the generated plot can be seen [here](https://huggingface.co/datasets/distilabel-internal-testing/distilabel-artifacts-example/blob/main/artifacts/count_text_characters_0/text_character_count_distribution/figure.png).

mkdocs.yml

@@ -7,6 +7,7 @@ site_description: Distilabel is an AI Feedback (AIF) framework for building data
 # Repository
 repo_name: argilla-io/distilabel
 repo_url: https://github.com/argilla-io/distilabel
+edit_uri: edit/main/docs/
 
 extra:
   version:
@@ -179,6 +180,7 @@ nav:
           - Using CLI to explore and re-run existing Pipelines: "sections/how_to_guides/advanced/cli/index.md"
           - Using a file system to pass data of batches between steps: "sections/how_to_guides/advanced/fs_to_pass_data.md"
           - Assigning resources to a step: "sections/how_to_guides/advanced/assigning_resources_to_step.md"
+          - Saving step generated artifacts: "sections/how_to_guides/advanced/saving_step_generated_artifacts.md"
           - Serving an LLM for sharing it between several tasks: "sections/how_to_guides/advanced/serving_an_llm_for_reuse.md"
           - Scaling and distributing a pipeline with Ray: "sections/how_to_guides/advanced/scaling_with_ray.md"
   - Pipeline Samples:

src/distilabel/constants.py

@@ -25,6 +25,16 @@
 CONVERGENCE_STEP_ATTR_NAME: Final[str] = "convergence_step"
 LAST_BATCH_SENT_FLAG: Final[str] = "last_batch_sent"
 
+# Data paths constants
+STEPS_OUTPUTS_PATH = "steps_outputs"
+STEPS_ARTIFACTS_PATH = "steps_artifacts"
+
+# Distiset related constants
+DISTISET_CONFIG_FOLDER: Final[str] = "distiset_configs"
+DISTISET_ARTIFACTS_FOLDER: Final[str] = "artifacts"
+PIPELINE_CONFIG_FILENAME: Final[str] = "pipeline.yaml"
+PIPELINE_LOG_FILENAME: Final[str] = "pipeline.log"
+
 
 __all__ = [
     "STEP_ATTR_NAME",