Vodalus / wiki.py
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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"
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 = 512
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()
def search(query):
print("Input question:", query)
##### Semantic 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 #####
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