Class Population

pymoo/core/population.py:10–125

class Population(np.ndarray):
    def __new__(cls, individuals: Individual | list[Individual] | None = None):
        individuals = individuals if individuals is not None else []
        if isinstance(individuals, Individual):
            individuals = [individuals]
        return np.array(individuals).view(cls)

    def has(self, key: str) -> bool:
        return all([ind.has(key) for ind in self])

    def collect(self, func: Callable, to_numpy: bool = True) -> list[Any] | np.ndarray:
        val: list[Any] = []
        for i in range(len(self)):
            val.append(func(self[i]))
        if to_numpy:
            return np.array(val)
        return val

    def apply(self, func: Callable) -> None:
        self.collect(func, to_numpy=False)

    def set(self, *args, **kwargs) -> Optional["Population"]:

        # if population is empty just return
        if self.size == 0:
            return None

        # done for the old interface with the interleaving variable definition
        kwargs = interleaving_args(*args, kwargs=kwargs)

        # for each entry in the dictionary set it to each individual
        for key, values in kwargs.items():
            is_iterable = hasattr(values, "__len__") and not isinstance(values, str)

            if is_iterable and len(values) != len(self):
                raise Exception(
                    "Population Set Attribute Error: Number of values and population size do not match!"
                )

            for i in range(len(self)):
                val = values[i] if is_iterable else values

                # check for view and make copy to prevent memory leakage (#455)
                if isinstance(val, np.ndarray) and not val.flags["OWNDATA"]:
                    val = val.copy()

                self[i].set(key, val)

        return self

    def get(self, *args, to_numpy: bool = True, **kwargs) -> Any | tuple[Any, ...]:

        val: dict[Any, list[Any]] = {}
        for c in args:
            val[c] = []

        # for each individual
        for i in range(len(self)):