Merge pull request #718 from realpython/python-llamaindex

Sample code for the article on LlamaIndex

Author: acsany

python-llamaindex/README.md

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+# LlamaIndex in Python: A RAG Guide With Examples
+
+This folder provides the code examples for the Real Python tutorial [LlamaIndex in Python: A RAG Guide With Examples](https://realpython.com/llamaindex-examples/).

python-llamaindex/async_query.py

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+import asyncio
+from pathlib import Path
+
+from llama_index.core import (
+    SimpleDirectoryReader,
+    StorageContext,
+    VectorStoreIndex,
+    load_index_from_storage,
+)
+
+# Define the storage directory
+BASE_DIR = Path(__file__).resolve().parent
+PERSIST_DIR = BASE_DIR / "storage"
+DATA_FILE = BASE_DIR / "data" / "pep8.rst"
+
+
+def get_index(persist_dir=PERSIST_DIR, data_file=DATA_FILE):
+    if persist_dir.exists():
+        storage_context = StorageContext.from_defaults(
+            persist_dir=str(persist_dir),
+        )
+        index = load_index_from_storage(storage_context)
+        print("Index loaded from storage...")
+    else:
+        reader = SimpleDirectoryReader(input_files=[str(data_file)])
+        documents = reader.load_data()
+        index = VectorStoreIndex.from_documents(documents)
+        index.storage_context.persist(persist_dir=str(persist_dir))
+        print("Index created and persisted to storage...")
+
+    return index
+
+
+async def main():
+    index = get_index()
+    query_engine = index.as_query_engine()
+
+    queries = [
+        "What is this document about?",
+        "Summarize the naming conventions in Python?",
+    ]
+
+    # Run queries asynchronously
+    tasks = [query_engine.aquery(query) for query in queries]
+    responses = await asyncio.gather(*tasks)
+
+    # Print responses
+    for i, (query, response) in enumerate(zip(queries, responses), 1):
+        print(f"\nQuery {i}: {query}")
+        print(f"Response: {response}\n")
+        print("-" * 80)
+
+
+if __name__ == "__main__":
+    asyncio.run(main())