MaartenGr/BERTopic: v0.14.0

<h1><b>Highlights</a></b></h1>

• Fine-tune topic representations with bertopic.representation
  • Diverse range of models, including KeyBERT, MMR, POS, Transformers, OpenAI, and more!'
  • Create your own prompts for text generation models, like GPT3:
    • Use "[KEYWORDS]" and "[DOCUMENTS]" in the prompt to decide where the keywords and and set of representative documents need to be inserted.
  • Chain models to perform fine-grained fine-tuning
  • Create and customize your represention model
• Improved the topic reduction technique when using nr_topics=int
• Added title parameters for all graphs (#800)

<h1><b>Fixes</a></b></h1>

• Improve documentation (#837, #769, #954, #912, #911)
• Bump pyyaml (#903)
• Fix large number of representative docs (#965)
• Prevent stochastisch behavior in .visualize_topics (#952)
• Add custom labels parameter to .visualize_topics (#976)
• Fix cuML HDBSCAN type checks by @FelSiq in #981

<h2><b>API Changes</a></b></h2>

• The diversity parameter was removed in favor of bertopic.representation.MaximalMarginalRelevance
• The representation_model parameter was added to bertopic.BERTopic

<br>

<h1><b><a href="https://maartengr.github.io/BERTopic/getting_started/representation/representation.html">Representation Models</a></b></h1>

Fine-tune the c-TF-IDF representation with a variety of models. Whether that is through a KeyBERT-Inspired model or GPT-3, the choice is up to you!

<iframe width="1200" height="500" src="https://user-images.githubusercontent.com/25746895/218417067-a81cc179-9055-49ba-a2b0-f2c1db535159.mp4 " title="BERTopic Overview" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

<br>

<h2><b><a href="https://maartengr.github.io/BERTopic/getting_started/representation/representation.html#keybertinspired">KeyBERTInspired</a></b></h2>

The algorithm follows some principles of KeyBERT but does some optimization in order to speed up inference. Usage is straightforward:

from bertopic.representation import KeyBERTInspired
from bertopic import BERTopic
# Create your representation model
representation_model = KeyBERTInspired()
# Use the representation model in BERTopic on top of the default pipeline
topic_model = BERTopic(representation_model=representation_model)

<h2><b><a href="https://maartengr.github.io/BERTopic/getting_started/representation/representation.html#partofspeech">PartOfSpeech</a></b></h2>

Our candidate topics, as extracted with c-TF-IDF, do not take into account a keyword's part of speech as extracting noun-phrases from all documents can be computationally quite expensive. Instead, we can leverage c-TF-IDF to perform part of speech on a subset of keywords and documents that best represent a topic.

from bertopic.representation import PartOfSpeech
from bertopic import BERTopic
# Create your representation model
representation_model = PartOfSpeech("en_core_web_sm")
# Use the representation model in BERTopic on top of the default pipeline
topic_model = BERTopic(representation_model=representation_model)

<h2><b><a href="https://maartengr.github.io/BERTopic/getting_started/representation/representation.html#maximalmarginalrelevance">MaximalMarginalRelevance</a></b></h2>

When we calculate the weights of keywords, we typically do not consider whether we already have similar keywords in our topic. Words like "car" and "cars" essentially represent the same information and often redundant. We can use MaximalMarginalRelevance to improve diversity of our candidate topics:

from bertopic.representation import MaximalMarginalRelevance
from bertopic import BERTopic
# Create your representation model
representation_model = MaximalMarginalRelevance(diversity=0.3)
# Use the representation model in BERTopic on top of the default pipeline
topic_model = BERTopic(representation_model=representation_model)

<h2><b><a href="https://maartengr.github.io/BERTopic/getting_started/representation/representation.html#zero-shot-classification">Zero-Shot Classification</a></b></h2>

To perform zero-shot classification, we feed the model with the keywords as generated through c-TF-IDF and a set of candidate labels. If, for a certain topic, we find a similar enough label, then it is assigned. If not, then we keep the original c-TF-IDF keywords.

We use it in BERTopic as follows:

from bertopic.representation import ZeroShotClassification
from bertopic import BERTopic
# Create your representation model
candidate_topics = ["space and nasa", "bicycles", "sports"]
representation_model = ZeroShotClassification(candidate_topics, model="facebook/bart-large-mnli")
# Use the representation model in BERTopic on top of the default pipeline
topic_model = BERTopic(representation_model=representation_model)

<h2><b><a href="https://maartengr.github.io/BERTopic/getting_started/representation/representation.html#transformers">Text Generation: 🤗 Transformers</a></b></h2>

Nearly every week, there are new and improved models released on the 🤗 Model Hub that, with some creativity, allow for further fine-tuning of our c-TF-IDF based topics. These models range from text generation to zero-classification. In BERTopic, wrappers around these methods are created as a way to support whatever might be released in the future.

Using a GPT-like model from the huggingface hub is rather straightforward:

from bertopic.representation import TextGeneration
from bertopic import BERTopic
# Create your representation model
representation_model = TextGeneration('gpt2')
# Use the representation model in BERTopic on top of the default pipeline
topic_model = BERTopic(representation_model=representation_model)

<h2><b><a href="https://maartengr.github.io/BERTopic/getting_started/representation/representation.html#cohere">Text Generation: Cohere</a></b></h2>

Instead of using a language model from 🤗 transformers, we can use external APIs instead that do the work for you. Here, we can use Cohere to extract our topic labels from the candidate documents and keywords. To use this, you will need to install cohere first:

pip install cohere

Then, get yourself an API key and use Cohere's API as follows:

import cohere
from bertopic.representation import Cohere
from bertopic import BERTopic
# Create your representation model
co = cohere.Client(my_api_key)
representation_model = Cohere(co)
# Use the representation model in BERTopic on top of the default pipeline
topic_model = BERTopic(representation_model=representation_model)

<h2><b><a href="https://maartengr.github.io/BERTopic/getting_started/representation/representation.html#openai">Text Generation: OpenAI</a></b></h2>

Instead of using a language model from 🤗 transformers, we can use external APIs instead that do the work for you. Here, we can use OpenAI to extract our topic labels from the candidate documents and keywords. To use this, you will need to install openai first:

pip install openai

Then, get yourself an API key and use OpenAI's API as follows:

import openai
from bertopic.representation import OpenAI
from bertopic import BERTopic
# Create your representation model
openai.api_key = MY_API_KEY
representation_model = OpenAI()
# Use the representation model in BERTopic on top of the default pipeline
topic_model = BERTopic(representation_model=representation_model)

<h2><b><a href="https://maartengr.github.io/BERTopic/getting_started/representation/representation.html#langchain">Text Generation: LangChain</a></b></h2>

Langchain is a package that helps users with chaining large language models. In BERTopic, we can leverage this package in order to more efficiently combine external knowledge. Here, this external knowledge are the most representative documents in each topic.

To use langchain, you will need to install the langchain package first. Additionally, you will need an underlying LLM to support langchain, like openai:

pip install langchain, openai

Then, you can create your chain as follows:

from langchain.chains.question_answering import load_qa_chain
from langchain.llms import OpenAI
chain = load_qa_chain(OpenAI(temperature=0, openai_api_key=MY_API_KEY), chain_type="stuff")

Finally, you can pass the chain to BERTopic as follows:

from bertopic.representation import LangChain
# Create your representation model
representation_model = LangChain(chain)
# Use the representation model in BERTopic on top of the default pipeline
topic_model = BERTopic(representation_model=representation_model)