Source code for gene

"""This module defines the Gene class.

This module defines the Gene class, used to create each individual's genes.
It defines the methods allowed on genes, including the mutations.
"""
from __future__ import annotations
from typing import Union

from copy import deepcopy
import numpy as np

class Gene:
  """The Gene class, used to define an individual's genes.

  Defines an individual's gene, performs the mutations of an individual's genes.
  """
  def __init__(
    self,
    gene_type:type,
    minimum:Union[int, float],
    maximum:Union[int, float],
    constraint:str="Soft",
  ) -> None:
    """Inits Individual's gene given a gene type, minimum and maximum values."""
    self.type:type = gene_type
    self.gene:Union[int, float] = self._init_gene(minimum, maximum)
    self.minimum:Union[int, float] = minimum
    self.maximum:Union[int, float] = maximum
    self.constraint:str = constraint

  def _init_gene(
    self,
    minimum:Union[int, float],
    maximum:Union[int, float],
  ) -> Union[int, float]:
    """Inits Individual's gene given a gene type, minimum and maximum values."""
    if self.type == int:
      return np.random.randint(low=minimum, high=maximum)
    elif self.type == float:
      return np.random.uniform(low=minimum, high=maximum)
    else:
      print("Error: Type not recognized. Defaulting to float type")
      return np.random.uniform(low=minimum, high=maximum)

  def mutate(self) -> None:
    """Performs a random mutation on the gene."""
    if self.type == int:
      mutation = np.random.randn(1).astype(int)[0]
    elif self.type == float:
      mutation = np.random.randn(1)[0]
    if self.constraint == "Hard":
      if (
        self.gene+mutation < self.maximum and self.gene+mutation > self.minimum
      ):
        self.gene += mutation
    else:
      self.gene += mutation

  def value(self) -> Union[int, float]:
    """Returns the gene's value."""
    return self.gene

  def copy(self) -> Gene:
    """Returns a deepcopy of the gene."""
    return deepcopy(self)