Add LiteLLM as a representation model (MaartenGr#2213)

bertopic/cluster/_base.py

@@ -14,7 +14,7 @@ class BaseCluster:
 
     ```python
     from bertopic import BERTopic
-    from bertopic.dimensionality import BaseCluster
+    from bertopic.cluster import BaseCluster
 
     empty_cluster_model = BaseCluster()
 

bertopic/representation/__init__.py

@@ -33,6 +33,13 @@
     msg = "`pip install openai` \n\n"
     OpenAI = NotInstalled("OpenAI", "openai", custom_msg=msg)
 
+# LiteLLM Generator
+try:
+    from bertopic.representation._litellm import LiteLLM
+except ModuleNotFoundError:
+    msg = "`pip install litellm` \n\n"
+    LiteLLM = NotInstalled("LiteLLM", "litellm", custom_msg=msg)
+
 # LangChain Generator
 try:
     from bertopic.representation._langchain import LangChain
@@ -63,6 +70,7 @@
     "Cohere",
     "OpenAI",
     "LangChain",
+    "LiteLLM",
     "LlamaCPP",
     "VisualRepresentation",
 ]

bertopic/representation/_litellm.py

@@ -0,0 +1,176 @@
+import time
+from litellm import completion
+import pandas as pd
+from scipy.sparse import csr_matrix
+from typing import Mapping, List, Tuple, Any
+from bertopic.representation._base import BaseRepresentation
+from bertopic.representation._utils import retry_with_exponential_backoff
+
+
+DEFAULT_PROMPT = """
+I have a topic that contains the following documents: 
+[DOCUMENTS]
+The topic is described by the following keywords: [KEYWORDS]
+Based on the information above, extract a short topic label in the following format:
+topic: <topic label>
+"""
+
+
+class LiteLLM(BaseRepresentation):
+    """Using the LiteLLM API to generate topic labels.
+
+    For an overview of models see:
+    https://docs.litellm.ai/docs/providers
+
+    Arguments:
+        model: Model to use. Defaults to OpenAI's "gpt-3.5-turbo".
+        generator_kwargs: Kwargs passed to `litellm.completion`.
+        prompt: The prompt to be used in the model. If no prompt is given,
+                `self.default_prompt_` is used instead.
+                NOTE: Use `"[KEYWORDS]"` and `"[DOCUMENTS]"` in the prompt
+                to decide where the keywords and documents need to be
+                inserted.
+        delay_in_seconds: The delay in seconds between consecutive prompts
+                          in order to prevent RateLimitErrors.
+        exponential_backoff: Retry requests with a random exponential backoff.
+                             A short sleep is used when a rate limit error is hit,
+                             then the requests is retried. Increase the sleep length
+                             if errors are hit until 10 unsuccesfull requests.
+                             If True, overrides `delay_in_seconds`.
+        nr_docs: The number of documents to pass to LiteLLM if a prompt
+                 with the `["DOCUMENTS"]` tag is used.
+        diversity: The diversity of documents to pass to LiteLLM.
+                   Accepts values between 0 and 1. A higher
+                   values results in passing more diverse documents
+                   whereas lower values passes more similar documents.
+
+    Usage:
+
+    To use this, you will need to install the litellm package first:
+
+    `pip install litellm`
+
+    Then, get yourself an API key of any provider (for instance OpenAI) and use it as follows:
+
+    ```python
+    import os
+    from bertopic.representation import LiteLLM
+    from bertopic import BERTopic
+
+    # set ENV variables
+    os.environ["OPENAI_API_KEY"] = "your-openai-key"
+
+    # Create your representation model
+    representation_model = LiteLLM(model="gpt-3.5-turbo")
+
+    # Use the representation model in BERTopic on top of the default pipeline
+    topic_model = BERTopic(representation_model=representation_model)
+    ```
+
+    You can also use a custom prompt:
+
+    ```python
+    prompt = "I have the following documents: [DOCUMENTS] \nThese documents are about the following topic: '"
+    representation_model = LiteLLM(model="gpt", prompt=prompt)
+    ```
+    """  # noqa: D301
+
+    def __init__(
+        self,
+        model: str = "gpt-3.5-turbo",
+        prompt: str = None,
+        generator_kwargs: Mapping[str, Any] = {},
+        delay_in_seconds: float = None,
+        exponential_backoff: bool = False,
+        nr_docs: int = 4,
+        diversity: float = None,
+    ):
+        self.model = model
+        self.prompt = prompt if prompt else DEFAULT_PROMPT
+        self.default_prompt_ = DEFAULT_PROMPT
+        self.delay_in_seconds = delay_in_seconds
+        self.exponential_backoff = exponential_backoff
+        self.nr_docs = nr_docs
+        self.diversity = diversity
+
+        self.generator_kwargs = generator_kwargs
+        if self.generator_kwargs.get("model"):
+            self.model = generator_kwargs.get("model")
+        if self.generator_kwargs.get("prompt"):
+            del self.generator_kwargs["prompt"]
+
+    def extract_topics(
+        self, topic_model, documents: pd.DataFrame, c_tf_idf: csr_matrix, topics: Mapping[str, List[Tuple[str, float]]]
+    ) -> Mapping[str, List[Tuple[str, float]]]:
+        """Extract topics.
+
+        Arguments:
+            topic_model: A BERTopic model
+            documents: All input documents
+            c_tf_idf: The topic c-TF-IDF representation
+            topics: The candidate topics as calculated with c-TF-IDF
+
+        Returns:
+            updated_topics: Updated topic representations
+        """
+        # Extract the top n representative documents per topic
+        repr_docs_mappings, _, _, _ = topic_model._extract_representative_docs(
+            c_tf_idf, documents, topics, 500, self.nr_docs, self.diversity
+        )
+
+        # Generate using a (Large) Language Model
+        updated_topics = {}
+        for topic, docs in repr_docs_mappings.items():
+            prompt = self._create_prompt(docs, topic, topics)
+
+            # Delay
+            if self.delay_in_seconds:
+                time.sleep(self.delay_in_seconds)
+
+            messages = [
+                {"role": "system", "content": "You are a helpful assistant."},
+                {"role": "user", "content": prompt},
+            ]
+            kwargs = {"model": self.model, "messages": messages, **self.generator_kwargs}
+            if self.exponential_backoff:
+                response = chat_completions_with_backoff(**kwargs)
+            else:
+                response = completion(**kwargs)
+            label = response["choices"][0]["message"]["content"].strip().replace("topic: ", "")
+
+            updated_topics[topic] = [(label, 1)]
+
+        return updated_topics
+
+    def _create_prompt(self, docs, topic, topics):
+        keywords = list(zip(*topics[topic]))[0]
+
+        # Use the Default Chat Prompt
+        if self.prompt == DEFAULT_PROMPT:
+            prompt = self.prompt.replace("[KEYWORDS]", " ".join(keywords))
+            prompt = self._replace_documents(prompt, docs)
+
+        # Use a custom prompt that leverages keywords, documents or both using
+        # custom tags, namely [KEYWORDS] and [DOCUMENTS] respectively
+        else:
+            prompt = self.prompt
+            if "[KEYWORDS]" in prompt:
+                prompt = prompt.replace("[KEYWORDS]", " ".join(keywords))
+            if "[DOCUMENTS]" in prompt:
+                prompt = self._replace_documents(prompt, docs)
+
+        return prompt
+
+    @staticmethod
+    def _replace_documents(prompt, docs):
+        to_replace = ""
+        for doc in docs:
+            to_replace += f"- {doc[:255]}\n"
+        prompt = prompt.replace("[DOCUMENTS]", to_replace)
+        return prompt
+
+
+def chat_completions_with_backoff(**kwargs):
+    return retry_with_exponential_backoff(
+        completion,
+    )(**kwargs)

docs/algorithm/algorithm.md

@@ -164,7 +164,12 @@ The following models are implemented in `bertopic.representation`:
 * `PartOfSpeech`
 * `KeyBERTInspired`
 * `ZeroShotClassification`
-* `TextGeneration`
+* `TextGeneration` (HuggingFace)
 * `Cohere`
 * `OpenAI`
 * `LangChain`
+* `LiteLLM`
+* `LlamaCPP`
+
+!!! tip Models
+    There are roughly two sets of models. **First** are the non-generative set of models that you can find [here](https://maartengr.github.io/BERTopic/getting_started/representation/representation.html). These include models that focus on enhancing the keywords in the topic representations. **Second** are the generative models that attempt to label or summarize the topics instead. You can find an overview of [implemented LLMs here](https://maartengr.github.io/BERTopic/getting_started/representation/llm).

docs/api/backends.md

@@ -0,0 +1,3 @@
+# `Backends`
+
+::: bertopic.backend

docs/api/cluster.md

@@ -0,0 +1,3 @@
+# `BaseCluster`
+
+::: bertopic.cluster._base.BaseCluster

docs/api/plotting.md

@@ -0,0 +1,3 @@
+# `Plotting`
+
+::: bertopic.plotting

docs/api/representations.md

@@ -0,0 +1,3 @@
+# `Representations`
+
+::: bertopic.representation

docs/api/vectorizers.md

@@ -0,0 +1,3 @@
+# `Vectorizers`
+
+::: bertopic.vectorizers._online_cv.OnlineCountVectorizer