Add more docstrings for ElasticsearchDocumentStore and ElasticsearchBM25Retriever

integrations/elasticsearch/src/elasticsearch_haystack/bm25_retriever.py

@@ -11,6 +11,34 @@
 
 @component
 class ElasticsearchBM25Retriever:
+    """
+    ElasticsearchBM25Retriever is a keyword-based retriever that uses BM25 to find the most
+    similar documents to a user's query.
+    This retriever is only compatible with ElasticsearchDocumentStore.
+
+    Usage example:
+    ```python
+    from haystack import Document
+    from elasticsearch_haystack.document_store import ElasticsearchDocumentStore
+    from elasticsearch_haystack.bm25_retriever import ElasticsearchBM25Retriever
+
+    document_store = ElasticsearchDocumentStore(hosts="http://localhost:9200")
+    retriever = ElasticsearchBM25Retriever(document_store=document_store)
+
+    # Add documents to DocumentStore
+    documents = [
+        Document(text="My name is Carla and I live in Berlin"),
+        Document(text="My name is Paul and I live in New York"),
+        Document(text="My name is Silvano and I live in Matera"),
+        Document(text="My name is Usagi Tsukino and I live in Tokyo"),
+    ]
+    document_store.write_documents(documents)
+
+    result = retriever.run(query="Who lives in Berlin?")
+    for doc in result["documents"]:
+        print(doc.text)
+    """
+
     def __init__(
         self,
         *,
@@ -20,6 +48,24 @@ def __init__(
         top_k: int = 10,
         scale_score: bool = False,
     ):
+        """
+        Initialize ElasticsearchBM25Retriever with an instance ElasticsearchDocumentStore.
+
+        :param document_store: An instance of ElasticsearchDocumentStore.
+        :type document_store: ElasticsearchDocumentStore
+        :param filters: Filters applied to the retrieved Documents, for more info
+                        see `ElasticsearchDocumentStore.filter_documents`, defaults to None
+        :type filters: Optional[Dict[str, Any]], optional
+        :param fuzziness: Fuzziness parameter passed to Elasticsearch, defaults to "AUTO".
+                          see the official documentation for valid values:
+                          https://www.elastic.co/guide/en/elasticsearch/reference/current/common-options.html#fuzziness
+        :type fuzziness: str, optional
+        :param top_k: Maximum number of Documents to return, defaults to 10
+        :type top_k: int, optional
+        :param scale_score: If `True` scales the Document`s scores between 0 and 1, defaults to False
+        :type scale_score: bool, optional
+        """
+
         if not isinstance(document_store, ElasticsearchDocumentStore):
             msg = "document_store must be an instance of ElasticsearchDocumentStore"
             raise ValueError(msg)

integrations/elasticsearch/src/elasticsearch_haystack/document_store.py

@@ -31,6 +31,31 @@
 
 
 class ElasticsearchDocumentStore:
+    """
+    ElasticsearchDocumentStore is a Document Store for Elasticsearch.
+    It can be used with Elastic Cloud or your own Elasticsearch cluster.
+
+    Simple usage with Elastic Cloud:
+    ```python
+    from haystack.document_store.elasticsearch import ElasticsearchDocumentStore
+    document_store = ElasticsearchDocumentStore(cloud_id="YOUR_CLOUD_ID", api_key="YOUR_API_KEY")
+    ```
+
+    One can also connect to a self-hosted Elasticsearch instance:
+    ```python
+    from haystack.document_store.elasticsearch import ElasticsearchDocumentStore
+    document_store = ElasticsearchDocumentStore(hosts="http://localhost:9200")
+    ```
+    In the above example we connect with security disabled just to show the basic usage.
+    We strongly recommend to enable security so that only authorized users can access your data.
+
+    For more details on how to connect to Elasticsearch and configure security,
+    see the official Elasticsearch documentation:
+    https://www.elastic.co/guide/en/elasticsearch/client/python-api/current/connecting.html
+
+    All extra keyword arguments will be passed to the Elasticsearch client.
+    """
+
     def __init__(
         self,
         *,
@@ -41,6 +66,11 @@ def __init__(
     ):
         """
         Creates a new ElasticsearchDocumentStore instance.
+        When no index is explicitly specified, it will use the default index "default".
+        It will also try to create that index if it doesn't exist yet. Otherwise it will use the existing one.
+
+        One can also set the similarity function used to compare Documents embeddings. This is mostly useful
+        when using the `ElasticsearchDocumentStore` in a Pipeline with an `ElasticsearchEmbeddingRetriever`.
 
         For more information on connection parameters, see the official Elasticsearch documentation:
         https://www.elastic.co/guide/en/elasticsearch/client/python-api/current/connecting.html