Flask application

import re
from flask import Flask, request, render_template

app = Flask(__name__)

# Simulated data: documents and their content
documents = {
    1: "Python is a popular programming language.",
    2: "Search engines help users find information.",
    3: "PageRank is used by Google to rank websites.",
    4: "Programming languages are used to build software.",
}

# Step 1: Indexing
index = {}
for doc_id, content in documents.items():
    words = re.findall(r'\w+', content.lower())
    for word in words:
        if word not in index:
            index[word] = []
        index[word].append(doc_id)

# Simplified PageRank
def pagerank(doc_id, query_results):
    relevance_score = 0
    for result in query_results:
        if result == doc_id:
            relevance_score += 1
    return relevance_score

@app.route('/', methods=['GET', 'POST'])
def search_page():
    if request.method == 'POST':
        user_query = request.form['query']
        query_results = search(user_query)
        
        ranked_results = []
        for doc_id in query_results:
            rank_score = pagerank(doc_id, query_results)
            ranked_results.append((doc_id, rank_score))
        
        ranked_results.sort(key=lambda x: x[1], reverse=True)
        return render_template('results.html', user_query=user_query, ranked_results=ranked_results)
    return render_template('index.html')

def search(query):
    query_words = query.lower().split()
    results = []
    for word in query_words:
        if word in index:
            results.extend(index[word])
    return list(set(results))  # Remove duplicates

if __name__ == '__main__':
    app.run(debug=True)