ndtools.abc module

class Equatable

Bases: ABC

Implement equality operations for multidimensional arrays.

Classes that inherit from this abstract base class and implement both __eq__ and __ne__ special methods can perform their own equality operations on multidimensional arrays. These special methods should be implemented for the target array like def __eq__(self, array). Then the class instance and the array can perform instance == array and array == instance.

Raises:

TypeError – Raised if both __eq__ and __ne__ are not defined.

Examples

import numpy as np
from ndtools import Equatable

class Even(Equatable):
    def __eq__(self, array):
        return array % 2 == 0

    def __ne__(self, array):
        return ~(self == array)

Even() == np.arange(3)  # -> array([True, False, True])
np.arange(3) == Even()  # -> array([True, False, True])

Even() != np.arange(3)  # -> array([False, True, False])
np.arange(3) != Even()  # -> array([False, True, False])

class Orderable

Bases: ABC

Implement ordering operations for multidimensional arrays.

Classes that inherit from this abstract base class and implement all of __eq__, __ge__, __gt__, __le__, __lt__, and __ne__ special methods can perform their own ordering operations on multidimensional arrays. These special methods should be implemented for the target array like def __ge__(self, array). Then the class instance and the array can perform instance >= array and array <= instance.

Raises:

TypeError – Raised if all of __eq__, __ge__, __gt__, __le__, __lt__, and __ne__ are not defined.

Examples

import numpy as np
from dataclasses import dataclass
from ndtools import Orderable

@dataclass
class Range(Orderable):
    lower: float
    upper: float

    def __eq__(self, array):
        return (array >= self.lower) & (array < self.upper)

    def __ge__(self, array):
        return array < self.upper

    def __gt__(self, array):
        return array < self.lower

    def __le__(self, array):
        return ~(self > array)

    def __lt__(self, array):
        return ~(self >= array)

    def __ne__(self, array):
        return ~(self == array)

Range(1, 2) == np.arange(3)  # -> array([False, True, False])
np.arange(3) == Range(1, 2)  # -> array([False, True, False])

Range(1, 2) >= np.arange(3)  # -> array([True, True, False])
np.arange(3) <= Range(1, 2)  # -> array([True, True, False])