amphora-wiki/src/search.py

import config

import os
import sys

from whoosh import scoring
from whoosh.index import create_in, open_dir
from whoosh.fields import Schema, TEXT, ID
from whoosh.qparser import QueryParser

INDEX_DIR = "indexdir"
DEF_TOPN = 10
ENTRY_DIR = config.ENTRY_DIR


def createSearchableData(root):
    """

    Schema definition: title(name of file), path(as ID), content(indexed but not stored), textdata (stored text content)
    source:
    https://appliedmachinelearning.blog/2018/07/31/developing-a-fast-indexing-and-full-text-search-engine-with-whoosh-a-pure-pythhon-library/
    """
    schema = Schema(title=TEXT(stored=True),
                    path=ID(stored=True), content=TEXT)
    if not os.path.exists(INDEX_DIR):
        os.mkdir(INDEX_DIR)
    ix = create_in(INDEX_DIR, schema)
    writer = ix.writer()
    for r, d, f in os.walk(root):
        for file in f:
            path = os.path.join(r, file)
            fp = open(path,encoding='utf-8')
            title = fp.readline()
            text = title + fp.read()
            writer.add_document(title=title, path=path, content=text)
            fp.close()
    writer.commit()


def search_times(query_str, topN):
    """
    Search for a given term and returns a specific amount of results.

    Parameters:
    query_str (string): term to search for
    topN (int): number of results to return

    Returns:
    string: html-formatted string including the hits of the search
    """
    ix = open_dir(INDEX_DIR)
    results = []
    with ix.searcher(weighting=scoring.BM25F) as s:
        query = QueryParser("content", ix.schema).parse(query_str)
        matches = s.search(query, limit=topN)
        for match in matches:
            results.append(
                {'title': match['title'], 'path': match['path'], 'match': match.score})
    return results


def search(query_str):
    """
    Search for a given term and show the predefined amount of results.

    Parameters:
    query_str (string): term to search for

    Returns:
    string: html-formatted string including the hits of the search
    """
    return search_times(query_str, DEF_TOPN)


createSearchableData(ENTRY_DIR)