model.py

"""
The model class for Mesa framework.

Core Objects: Model

"""
import random

# mypy
from typing import Any, Optional


class Model:
    """Base class for models."""

    def __new__(cls, *args: Any, **kwargs: Any) -> Any:
        """Create a new model object and instantiate its RNG automatically."""
        cls._seed = kwargs.get("seed", None)
        cls.random = random.Random(cls._seed)
        return object.__new__(cls)

    def __init__(self, *args: Any, **kwargs: Any) -> None:
        """Create a new model. Overload this method with the actual code to
        start the model.

        Attributes:
            schedule: schedule object
            running: a bool indicating if the model should continue running

        """

        self.running = True
        self.schedule = None
        self.current_id = 0

    def run_model(self) -> None:
        """Run the model until the end condition is reached. Overload as
        needed.

        """
        while self.running:
            self.step()

    def step(self) -> None:
        """A single step. Fill in here."""
        pass

    def next_id(self) -> int:
        """Return the next unique ID for agents, increment current_id"""
        self.current_id += 1
        return self.current_id

    def reset_randomizer(self, seed: Optional[int] = None) -> None:
        """Reset the model random number generator.

        Args:
            seed: A new seed for the RNG; if None, reset using the current seed
        """

        if seed is None:
            seed = self._seed
        self.random.seed(seed)
        self._seed = seed