Between

class overload_numpy.constraints.Between(lower_bound: type, upper_bound: type)

Bases: TypeConstraint

Type constrained between two types.

This combines the functionality of Covariant and Contravariant.

Parameters:

lower_boundtype

The child type of the argument.

upper_boundtype

The parent type of the argument.

Notes

When compiled this class permits interpreted subclasses, see https://mypyc.readthedocs.io/en/latest/native_classes.html

Examples

For this example we need a type hierarchy:

>>> class A: pass
>>> class B(A): pass
>>> class C(B): pass
>>> class D(C): pass
>>> class E(D): pass

Construct the constraint object:

>>> constraint = Between(D, B)

This can be used to validate argument types:

>>> constraint.validate_type(A)
False
>>> constraint.validate_type(B)
True
>>> constraint.validate_type(C)
True
>>> constraint.validate_type(D)
True
>>> constraint.validate_type(E)
False

Attributes:

bounds

Return tuple of (lower, upper) bounds.

Methods

validate_object(arg, /)	Validate an argument.
validate_type(arg_type, /)	Validate the argument type.

Attributes Summary

bounds

Return tuple of (lower, upper) bounds.

Methods Summary

validate_type(arg_type, /)

Validate the argument type.

Attributes Documentation

bounds

Return tuple of (lower, upper) bounds.

The lower bound is contravariant, the upper bound covariant.

Examples

For this example we need a type hierarchy:

>>> class A: pass
>>> class B(A): pass
>>> class C(B): pass

>>> constraint = Between(C, B)
>>> constraint.bounds
(C, B)

Methods Documentation

validate_type(arg_type: type, /) → bool

Validate the argument type.

This is used in overload_numpy.mixin.NPArrayFuncOverloadMixin and subclasses like overload_numpy.mixin.NPArrayOverloadMixin to ensure that the input is of the correct set of types to work with the __array_function__ override.

Parameters:

arg_typetype, positional-only

The type of the argument that must fit the type constraint.

Returns:

bool

Whether the type is valid.

Examples

The simplest built-in type constraint is overload_numpy.constraints.Invariant.

>>> from overload_numpy.constraints import Invariant
>>> constraint = Invariant(int)
>>> constraint.validate_type(int)  # exact type
True
>>> constraint.validate_type(bool)  # subclass
False