Empty index HnswDocumentIndex causes error next time script runs #1446
Description
When creating an empty HnswDocumentIndex, if there were no files indexed (.index called) then the next time the object is instantiated with the same work_dir it will fail.
Python version: 3.11.2
Docarray version: 0.30.0
Reproducible Example:
from docarray import BaseDoc
from docarray.typing import NdArray
from docarray.index import HnswDocumentIndex
class Text(BaseDoc):
embedding: NdArray[128]
text: str
index = HnswDocumentIndex[Text](work_dir="./index")Output:
Traceback (most recent call last):
File "/home/tim/Documents/git/_/docarray_example.py", line 11, in <module>
index = HnswDocumentIndex[Text](work_dir="./index")
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/tim/Documents/git/_/.venv/lib/python3.11/site-packages/docarray/index/backends/hnswlib.py", line 116, in __init__
self._hnsw_indices[col_name] = self._load_index(col_name, col)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/tim/Documents/git/_/.venv/lib/python3.11/site-packages/docarray/index/backends/hnswlib.py", line 386, in _load_index
index.load_index(self._hnsw_locations[col_name])
RuntimeError: Cannot open file