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import streamlit as st | |
from datasets import load_dataset | |
from sentence_transformers import SentenceTransformer, CrossEncoder, util | |
import torch | |
from huggingface_hub import hf_hub_download | |
embedding_path = "abokbot/wikipedia-embedding" | |
st.header("Wikipedia Search Engine app") | |
st_model_load = st.text('Loading embeddings, encoders and dataset (takes about 5min)') | |
def load_embedding(): | |
print("Loading embedding...") | |
path = hf_hub_download(repo_id="abokbot/wikipedia-embedding", filename="wikipedia_en_embedding.pt") | |
wikipedia_embedding = torch.load(path, map_location=torch.device('cpu')) | |
print("Embedding loaded!") | |
return wikipedia_embedding | |
wikipedia_embedding = load_embedding() | |
def load_encoders(): | |
print("Loading encoders...") | |
bi_encoder = SentenceTransformer('msmarco-MiniLM-L-6-v3') | |
bi_encoder.max_seq_length = 256 #Truncate long passages to 256 tokens | |
top_k = 32 | |
cross_encoder = CrossEncoder('cross-encoder/ms-marco-TinyBERT-L-2-v2') | |
print("Encoders loaded!") | |
return bi_encoder, cross_encoder | |
bi_encoder, cross_encoder = load_encoders() | |
def load_wikipedia_dataset(): | |
print("Loading wikipedia dataset...") | |
dataset = load_dataset("abokbot/wikipedia-first-paragraph")["train"] | |
print("Dataset loaded!") | |
return dataset | |
dataset = load_wikipedia_dataset() | |
st.success('Search engine ready') | |
st_model_load.text("") | |
if 'text' not in st.session_state: | |
st.session_state.text = "" | |
st.markdown("Enter query") | |
st_text_area = st.text_area( | |
'E.g. What is the hashing trick? or Largest city in Morocco', | |
value=st.session_state.text, | |
height=25 | |
) | |
def search(): | |
st.session_state.text = st_text_area | |
query = st_text_area | |
print("Input question:", query) | |
##### Sematic Search ##### | |
print("Semantic Search") | |
# Encode the query using the bi-encoder and find potentially relevant passages | |
top_k = 32 | |
question_embedding = bi_encoder.encode(query, convert_to_tensor=True) | |
hits = util.semantic_search(question_embedding, wikipedia_embedding, top_k=top_k) | |
hits = hits[0] # Get the hits for the first query | |
##### Re-Ranking ##### | |
# Now, score all retrieved passages with the cross_encoder | |
print("Re-Ranking") | |
cross_inp = [[query, dataset[hit['corpus_id']]["text"]] for hit in hits] | |
cross_scores = cross_encoder.predict(cross_inp) | |
# Sort results by the cross-encoder scores | |
for idx in range(len(cross_scores)): | |
hits[idx]['cross-score'] = cross_scores[idx] | |
hits = sorted(hits, key=lambda x: x['cross-score'], reverse=True) | |
# Output of top-3 hits from re-ranker | |
print("\n-------------------------\n") | |
print("Top-3 Cross-Encoder Re-ranker hits") | |
results = [] | |
for hit in hits[:3]: | |
results.append( | |
{ | |
"score": round(hit['cross-score'], 3), | |
"title": dataset[hit['corpus_id']]["title"], | |
"abstract": dataset[hit['corpus_id']]["text"].replace("\n", " "), | |
"link": dataset[hit['corpus_id']]["url"] | |
} | |
) | |
return results | |
# search button | |
st_search_button = st.button('Search') | |
if st_search_button: | |
results = search() | |
st.subheader("Top-3 Search results") | |
for i, result in enumerate(results): | |
st.markdown(f"#### Result {i+1}") | |
st.markdown("**Wikipedia article:** " + result["title"]) | |
st.markdown("**Link:** " + result["link"]) | |
st.markdown("**First paragraph:** " + result["abstract"]) | |
st.text("") |