fix: restore compatibility with previous loading method but remove fr…

…om README

README.md

@@ -149,23 +149,13 @@ results = RAG.search(query)
 ```
 
 This is the preferred way of doing things, since every index saves the full configuration of the model used to create it, and you can easily load it back up.
-However, if you'd rather do it yourself or want to use a slightly different configuration, you can spin-up an instance of `RAGPretrainedModel` and specify the index you want to use:
-
-```python
-from ragatouille import RAGPretrainedModel
-
-query = "What manga did Hayao Miyazaki write?"
-RAG = RAGPretrainedModel.from_pretrained("colbert-ir/colbertv2.0")
-results = RAG.search(query, index_name="my_index")
-```
 
 `RAG.search` is a flexible method! You can set the `k` value to however many results you want (it defaults to `10`), and you can also use it to search for multiple queries at once:
 
 ```python
 RAG.search(["What manga did Hayao Miyazaki write?",
 "Who are the founders of Ghibli?"
-"Who is the director of Spirited Away?"],
-index_name="my_index")
+"Who is the director of Spirited Away?"],)
 ```
 
 `RAG.search` returns results in the form of a list of dictionaries, or a list of list of dictionaries if you used multiple queries: 

ragatouille/models/colbert.py

@@ -30,6 +30,8 @@ def __init__(
         if n_gpu == -1:
             n_gpu = 1 if torch.cuda.device_count() == 0 else torch.cuda.device_count()
 
+        self.loaded_from_index = load_from_index
+
         if load_from_index:
             ckpt_config = ColBERTConfig.load_from_index(
                 str(pretrained_model_name_or_path)
@@ -104,12 +106,32 @@ def add_to_index(
             "add_to_index support will be more thorough in future versions",
         )
 
+        if self.loaded_from_index:
+            index_root = self.config.root
+        else:
+            index_root = str(
+                Path(self.config.root)
+                / Path(self.config.experiment)
+                / "indexes"
+            )
+            if not self.collection:
+                self.collection = self._get_collection_from_file(
+                    str(
+                        Path(self.config.root)
+                        / Path(self.config.experiment)
+                        / "indexes"
+                        / self.index_name
+                        / "collection.json"
+                    )
+                )
+
+
         searcher = Searcher(
             checkpoint=self.checkpoint,
             config=None,
             collection=self.collection,
             index=self.index_name,
-            index_root=self.config.root,
+            index_root=index_root,
             verbose=self.verbose,
         )
         new_documents = list(set(new_documents))