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dspy.ReAct

Constructor​

The constructor initializes the ReAct class and sets up its attributes. It is specifically designed to compose the interleaved steps of Thought, Action, and Observation.

import dsp
import dspy
from ..primitives.program import Module
from .predict import Predict

class ReAct(Module):
    def __init__(self, signature, max_iters=5, num_results=3, tools=None):
        ...

Parameters:

  • signature (Any): Signature of the predictive model.
  • max_iters (int, optional): Maximum number of iterations for the Thought-Action-Observation cycle. Defaults to 5.
  • num_results (int, optional): Number of results to retrieve in the action step. Defaults to 3.
  • tools (List[dspy.Tool], optional): List of tools available for actions. If none is provided, a default Retrieve tool with num_results is used.

Methods​

_generate_signature(self, iters)​

Generates a signature for the Thought-Action-Observation cycle based on the number of iterations.

Parameters:

  • iters (int): Number of iterations.

Returns:

  • A dictionary representation of the signature.

act(self, output, hop)​

Processes an action and returns the observation or final answer.

Parameters:

  • output (dict): Current output from the Thought.
  • hop (int): Current iteration number.

Returns:

  • A string representing the final answer or None.

forward(self, **kwargs)​

Main method to execute the Thought-Action-Observation cycle for a given set of input fields.

Parameters:

  • **kwargs: Keyword arguments corresponding to input fields.

Returns:

  • A dspy.Prediction object containing the result of the ReAct process.

Examples​

# Define a simple signature for basic question answering
class BasicQA(dspy.Signature):
    """Answer questions with short factoid answers."""
    question = dspy.InputField()
    answer = dspy.OutputField(desc="often between 1 and 5 words")

# Pass signature to ReAct module
react_module = dspy.ReAct(BasicQA)

# Call the ReAct module on a particular input
question = 'What is the color of the sky?'
result = react_module(question=question)

print(f"Question: {question}")
print(f"Final Predicted Answer (after ReAct process): {result.answer}")