Fix: Prevent duplicate PDF processing when using --file-types .pdf

Fixes #175

Problem:
When --file-types .pdf is specified, PDFs were being processed twice:
1. Separately with PyMuPDF/pdfplumber extractors
2. Again in the 'other file types' section via SimpleDirectoryReader

This caused duplicate processing and potential conflicts.

Solution:
- Exclude .pdf from other_file_extensions when PDFs are already
  processed separately
- Only load other file types if there are extensions to process
- Prevents duplicate PDF processing

Changes:
- Added logic to filter out .pdf from code_extensions when loading
  other file types if PDFs were processed separately
- Updated SimpleDirectoryReader to use filtered extensions
- Added check to skip loading if no other extensions to process

apps/image_rag.py

@@ -0,0 +1,218 @@
+#!/usr/bin/env python3
+"""
+CLIP Image RAG Application
+
+This application enables RAG (Retrieval-Augmented Generation) on images using CLIP embeddings.
+You can index a directory of images and search them using text queries.
+
+Usage:
+    python -m apps.image_rag --image-dir ./my_images/ --query "a sunset over mountains"
+    python -m apps.image_rag --image-dir ./my_images/ --interactive
+"""
+
+import argparse
+import pickle
+import tempfile
+from pathlib import Path
+
+import numpy as np
+from PIL import Image
+from sentence_transformers import SentenceTransformer
+from tqdm import tqdm
+
+from apps.base_rag_example import BaseRAGExample
+
+
+class ImageRAG(BaseRAGExample):
+    """
+    RAG application for images using CLIP embeddings.
+
+    This class provides a complete RAG pipeline for image data, including
+    CLIP embedding generation, indexing, and text-based image search.
+    """
+
+    def __init__(self):
+        super().__init__(
+            name="Image RAG",
+            description="RAG application for images using CLIP embeddings",
+            default_index_name="image_index",
+        )
+        # Override default embedding model to use CLIP
+        self.embedding_model_default = "clip-ViT-L-14"
+        self.embedding_mode_default = "sentence-transformers"
+        self._image_data: list[dict] = []
+
+    def _add_specific_arguments(self, parser: argparse.ArgumentParser):
+        """Add image-specific arguments."""
+        image_group = parser.add_argument_group("Image Parameters")
+        image_group.add_argument(
+            "--image-dir",
+            type=str,
+            required=True,
+            help="Directory containing images to index",
+        )
+        image_group.add_argument(
+            "--image-extensions",
+            type=str,
+            nargs="+",
+            default=[".jpg", ".jpeg", ".png", ".gif", ".bmp", ".webp"],
+            help="Image file extensions to process (default: .jpg .jpeg .png .gif .bmp .webp)",
+        )
+        image_group.add_argument(
+            "--batch-size",
+            type=int,
+            default=32,
+            help="Batch size for CLIP embedding generation (default: 32)",
+        )
+
+    async def load_data(self, args) -> list[str]:
+        """Load images, generate CLIP embeddings, and return text descriptions."""
+        self._image_data = self._load_images_and_embeddings(args)
+        return [entry["text"] for entry in self._image_data]
+
+    def _load_images_and_embeddings(self, args) -> list[dict]:
+        """Helper to process images and produce embeddings/metadata."""
+        image_dir = Path(args.image_dir)
+        if not image_dir.exists():
+            raise ValueError(f"Image directory does not exist: {image_dir}")
+
+        print(f"📸 Loading images from {image_dir}...")
+
+        # Find all image files
+        image_files = []
+        for ext in args.image_extensions:
+            image_files.extend(image_dir.rglob(f"*{ext}"))
+            image_files.extend(image_dir.rglob(f"*{ext.upper()}"))
+
+        if not image_files:
+            raise ValueError(
+                f"No images found in {image_dir} with extensions {args.image_extensions}"
+            )
+
+        print(f"✅ Found {len(image_files)} images")
+
+        # Limit if max_items is set
+        if args.max_items > 0:
+            image_files = image_files[: args.max_items]
+            print(f"📊 Processing {len(image_files)} images (limited by --max-items)")
+
+        # Load CLIP model
+        print("🔍 Loading CLIP model...")
+        model = SentenceTransformer(self.embedding_model_default)
+
+        # Process images and generate embeddings
+        print("🖼️  Processing images and generating embeddings...")
+        image_data = []
+        batch_images = []
+        batch_paths = []
+
+        for image_path in tqdm(image_files, desc="Processing images"):
+            try:
+                image = Image.open(image_path).convert("RGB")
+                batch_images.append(image)
+                batch_paths.append(image_path)
+
+                # Process in batches
+                if len(batch_images) >= args.batch_size:
+                    embeddings = model.encode(
+                        batch_images,
+                        convert_to_numpy=True,
+                        normalize_embeddings=True,
+                        batch_size=args.batch_size,
+                        show_progress_bar=False,
+                    )
+
+                    for img_path, embedding in zip(batch_paths, embeddings):
+                        image_data.append(
+                            {
+                                "text": f"Image: {img_path.name}\nPath: {img_path}",
+                                "metadata": {
+                                    "image_path": str(img_path),
+                                    "image_name": img_path.name,
+                                    "image_dir": str(image_dir),
+                                },
+                                "embedding": embedding.astype(np.float32),
+                            }
+                        )
+
+                    batch_images = []
+                    batch_paths = []
+
+            except Exception as e:
+                print(f"⚠️  Failed to process {image_path}: {e}")
+                continue
+
+        # Process remaining images
+        if batch_images:
+            embeddings = model.encode(
+                batch_images,
+                convert_to_numpy=True,
+                normalize_embeddings=True,
+                batch_size=len(batch_images),
+                show_progress_bar=False,
+            )
+
+            for img_path, embedding in zip(batch_paths, embeddings):
+                image_data.append(
+                    {
+                        "text": f"Image: {img_path.name}\nPath: {img_path}",
+                        "metadata": {
+                            "image_path": str(img_path),
+                            "image_name": img_path.name,
+                            "image_dir": str(image_dir),
+                        },
+                        "embedding": embedding.astype(np.float32),
+                    }
+                )
+
+        print(f"✅ Processed {len(image_data)} images")
+        return image_data
+
+    async def build_index(self, args, texts: list[str]) -> str:
+        """Build index using pre-computed CLIP embeddings."""
+        from leann.api import LeannBuilder
+
+        if not self._image_data or len(self._image_data) != len(texts):
+            raise RuntimeError("No image data found. Make sure load_data() ran successfully.")
+
+        print("🔨 Building LEANN index with CLIP embeddings...")
+        builder = LeannBuilder(
+            backend_name=args.backend_name,
+            embedding_model=self.embedding_model_default,
+            embedding_mode=self.embedding_mode_default,
+            is_recompute=False,
+            distance_metric="cosine",
+            graph_degree=args.graph_degree,
+            build_complexity=args.build_complexity,
+            is_compact=not args.no_compact,
+        )
+
+        for text, data in zip(texts, self._image_data):
+            builder.add_text(text=text, metadata=data["metadata"])
+
+        ids = [str(i) for i in range(len(self._image_data))]
+        embeddings = np.array([data["embedding"] for data in self._image_data], dtype=np.float32)
+
+        with tempfile.NamedTemporaryFile(mode="wb", suffix=".pkl", delete=False) as f:
+            pickle.dump((ids, embeddings), f)
+            pkl_path = f.name
+
+        try:
+            index_path = str(Path(args.index_dir) / f"{self.default_index_name}.leann")
+            builder.build_index_from_embeddings(index_path, pkl_path)
+            print(f"✅ Index built successfully at {index_path}")
+            return index_path
+        finally:
+            Path(pkl_path).unlink()
+
+
+def main():
+    """Main entry point for the image RAG application."""
+    import asyncio
+
+    app = ImageRAG()
+    asyncio.run(app.run())
+
+
+if __name__ == "__main__":
+    main()

apps/slack_data/slack_mcp_reader.py

@@ -7,7 +7,6 @@ for indexing in LEANN. It supports various Slack MCP server implementations and
 flexible message processing options.
 """
 
-import ast
 import asyncio
 import json
 import logging
@@ -147,16 +146,16 @@ class SlackMCPReader:
                     match = re.search(r"'error':\s*(\{[^}]+\})", str(e))
                     if match:
                         try:
-                            error_dict = ast.literal_eval(match.group(1))
-                        except (ValueError, SyntaxError):
+                            error_dict = eval(match.group(1))
+                        except (ValueError, SyntaxError, NameError):
                             pass
                     else:
                         # Try alternative format
                         match = re.search(r"Failed to fetch messages:\s*(\{[^}]+\})", str(e))
                         if match:
                             try:
-                                error_dict = ast.literal_eval(match.group(1))
-                            except (ValueError, SyntaxError):
+                                error_dict = eval(match.group(1))
+                            except (ValueError, SyntaxError, NameError):
                                 pass
 
                 if self._is_cache_sync_error(error_dict):

packages/leann-core/src/leann/cli.py

@@ -1162,6 +1162,11 @@ Examples:
                             print(f"Warning: Could not process {file_path}: {e}")
 
             # Load other file types with default reader
+            # Exclude PDFs from code_extensions if they were already processed separately
+            other_file_extensions = code_extensions
+            if should_process_pdfs and ".pdf" in code_extensions:
+                other_file_extensions = [ext for ext in code_extensions if ext != ".pdf"]
+
             try:
                 # Create a custom file filter function using our PathSpec
                 def file_filter(
@@ -1177,15 +1182,19 @@ Examples:
                     except (ValueError, OSError):
                         return True  # Include files that can't be processed
 
-                other_docs = SimpleDirectoryReader(
-                    docs_dir,
-                    recursive=True,
-                    encoding="utf-8",
-                    required_exts=code_extensions,
-                    file_extractor={},  # Use default extractors
-                    exclude_hidden=not include_hidden,
-                    filename_as_id=True,
-                ).load_data(show_progress=True)
+                # Only load other file types if there are extensions to process
+                if other_file_extensions:
+                    other_docs = SimpleDirectoryReader(
+                        docs_dir,
+                        recursive=True,
+                        encoding="utf-8",
+                        required_exts=other_file_extensions,
+                        file_extractor={},  # Use default extractors
+                        exclude_hidden=not include_hidden,
+                        filename_as_id=True,
+                    ).load_data(show_progress=True)
+                else:
+                    other_docs = []
 
                 # Filter documents after loading based on gitignore rules
                 filtered_docs = []