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Autocomplete with Whoosh-NG

Whoosh-NG provides autocomplete functionality through the whoosh_modern.autocomplete module.

Install​

pip install "whoosh-ng[autocomplete]"

Schema with Keyword Field for Terms​

from whoosh import index
from whoosh.fields import Schema, TEXT, KEYWORD

schema = Schema(
    title=TEXT(stored=True),
    tags=KEYWORD(stored=True, commas=True),
)

ix = index.create_in("autocomplete_index", schema)

Index Documents​

with ix.writer() as w:
    w.add_document(title="Python Programming", tags="python,programming,language")
    w.add_document(title="JavaScript Basics", tags="javascript,programming,web")
    w.add_document(title="Machine Learning", tags="ml,ai,data-science")
    w.add_document(title="Deep Learning", tags="ml,ai,neural-networks")
    w.commit()

Basic Autocomplete​

from whoosh_modern.autocomplete import create_autocomplete

# Create an autocomplete provider (supports "inverted" provider type)
provider = create_autocomplete("inverted")

# Add phrases to index
provider.add(["python", "programming", "javascript", "machine learning", "deep learning"])

# Search for suggestions
hits = provider.search("py", limit=5)
for hit in hits:
    print(hit.text, hit.score)
# Output: python 1.5, programming 0.2

Real-time Suggestion Endpoint​

from fastapi import FastAPI
from whoosh_modern.autocomplete import create_autocomplete

app = FastAPI()
provider = create_autocomplete("inverted")

# Populate provider with terms from your index
# (typically done during indexing)
provider.add(["python", "programming", "javascript", "machine learning"])

@app.get("/suggest")
async def suggest(q: str, limit: int = 5):
    hits = provider.search(q, limit=limit)
    return {"suggestions": [hit.text for hit in hits]}

Key Points​

  • Install with pip install whoosh-ng[autocomplete].
  • Use KEYWORD fields to store multi-value tags/terms.
  • Use create_autocomplete("inverted") to create a provider.
  • The InvertedIndexAutocomplete provider supports prefix matching with scoring.
  • Each result is an AutocompleteHit with text and score attributes.