Make sentence_transformers an optional dependency (#674)

* fix: Make sentence_transformers an optional dependency

- Move sentence_transformers to optional dependencies in pyproject.toml
- Add conditional import in features.py
- Update __init__.py to only export SentenceTransformerEmbed when available
- Add installation instructions to examples

Fixes #636

* Update examples for optional sentence_transformers dependency

- Add sentence-transformers to pyproject.toml dependencies in all 7 examples
- Update README files with installation instructions for SentenceTransformerEmbed
- Add clear dependency notes to examples that use sentence transformers

Part of #636

* docs: update installation instructions for optional sentence-transformers dependency

- Update quickstart.md: change pip install command to include [sentence-transformers] extra
- Update functions.md: add optional dependency note for SentenceTransformerEmbed function
- Remove manual 'pip install sentence-transformers' instructions from all example README.md and main.py files

* reverted the extra indents in quickstart.md

* rename optional dependency group to 'embeddings'

- Updated pyproject.toml to use [embeddings] instead of [sentence-transformers] for the optional dependency group
- Replaced all install instructions using 'cocoindex[sentence-transformers]' with 'cocoindex[embeddings]' across docs and examples
-

Author: theparthgupta

docs/docs/getting_started/quickstart.md

@@ -21,7 +21,7 @@ We'll need to install a bunch of dependencies for this project.
 1.  Install CocoIndex:
 
     ```bash
-    pip install -U cocoindex
+    pip install -U 'cocoindex[embeddings]'
     ```
 
 2.  You can skip this step if you already have a Postgres database with pgvector extension installed.

docs/docs/ops/functions.md

@@ -77,6 +77,15 @@ Return: [*KTable*](/docs/core/data_types#ktable), each row represents a chunk, w
 
 `SentenceTransformerEmbed` embeds a text into a vector space using the [SentenceTransformer](https://huggingface.co/sentence-transformers) library.
 
+:::note Optional Dependency Required
+
+This function requires the 'sentence-transformers' library, which is an optional dependency. Install CocoIndex with:
+
+```bash
+pip install 'cocoindex[embeddings]'
+```
+:::
+
 The spec takes the following fields:
 
 *   `model` (`str`): The name of the SentenceTransformer model to use.

examples/amazon_s3_embedding/pyproject.toml

@@ -3,7 +3,7 @@ name = "amazon-s3-text-embedding"
 version = "0.1.0"
 description = "Simple example for cocoindex: build embedding index based on Amazon S3 files."
 requires-python = ">=3.11"
-dependencies = ["cocoindex>=0.1.52", "python-dotenv>=1.0.1"]
+dependencies = ["cocoindex[embeddings]>=0.1.52", "python-dotenv>=1.0.1"]
 
 [tool.setuptools]
 packages = []

examples/code_embedding/pyproject.toml

@@ -3,7 +3,7 @@ name = "code-embedding"
 version = "0.1.0"
 description = "Simple example for cocoindex: build embedding index based on source code."
 requires-python = ">=3.11"
-dependencies = ["cocoindex>=0.1.56", "python-dotenv>=1.0.1"]
+dependencies = ["cocoindex[embeddings]>=0.1.56", "python-dotenv>=1.0.1"]
 
 [tool.setuptools]
 packages = []

examples/fastapi_server_docker/requirements.txt

@@ -1,4 +1,4 @@
-cocoindex>=0.1.52
+cocoindex[embeddings]>=0.1.52
 python-dotenv>=1.0.1
 fastapi==0.115.12
 fastapi-cli==0.0.7

examples/gdrive_text_embedding/pyproject.toml

@@ -3,7 +3,7 @@ name = "gdrive-text-embedding"
 version = "0.1.0"
 description = "Simple example for cocoindex: build embedding index based on Google Drive files."
 requires-python = ">=3.11"
-dependencies = ["cocoindex>=0.1.52", "python-dotenv>=1.0.1"]
+dependencies = ["cocoindex[embeddings]>=0.1.52", "python-dotenv>=1.0.1"]
 
 [tool.setuptools]
 packages = []

examples/pdf_embedding/pyproject.toml

@@ -4,7 +4,7 @@ version = "0.1.0"
 description = "Simple example for cocoindex: build embedding index based on local PDF files."
 requires-python = ">=3.11"
 dependencies = [
-    "cocoindex>=0.1.52",
+    "cocoindex[embeddings]>=0.1.52",
     "python-dotenv>=1.0.1",
     "marker-pdf>=1.5.2",
 ]

examples/text_embedding/pyproject.toml

@@ -4,7 +4,7 @@ version = "0.1.0"
 description = "Simple example for cocoindex: build embedding index based on local text files."
 requires-python = ">=3.11"
 dependencies = [
-    "cocoindex>=0.1.52",
+    "cocoindex[embeddings]>=0.1.52",
     "python-dotenv>=1.0.1",
     "pgvector>=0.4.1",
     "psycopg[binary,pool]",

examples/text_embedding_qdrant/README.md

@@ -37,6 +37,7 @@ We use Qdrant client to query the index, and reuse the embedding operation in th
    pip install -e .
    ```
 
+
 - Setup:
 
    ```bash

examples/text_embedding_qdrant/pyproject.toml

@@ -4,7 +4,7 @@ version = "0.1.0"
 description = "Simple example for cocoindex: build embedding index based on local text files."
 requires-python = ">=3.11"
 dependencies = [
-    "cocoindex>=0.1.52",
+    "cocoindex[embeddings]>=0.1.52",
     "python-dotenv>=1.0.1",
     "qdrant-client>=1.6.0",
 ]