Runtime Argument Class

class Argument(key, type_var, *, allowed_values=empty, kind=ArgumentKind.POSITIONAL_OR_KEYWORD, default=empty, value=empty)

Purpose

Argument is a runtime container for one typed argument definition and its value.

Key methods

from_param(param)

Build from an inspect.Parameter.

import inspect

param = next(iter(inspect.signature(lambda x: x).parameters.values()))
Argument.from_param(param)

set_default(default), set(value, *, key=None)

Set the default or current value.

arg.set_default(2)
arg.set(5)

add(value), remove(key=None)

Manage variadic argument storage.

validate(value, throw=True)

Type-check a proposed value.

arg.validate(3)

copy(**kwargs)

Clone the definition.

Behavior notes

Variadic keyword arguments store their values inside an internal Arguments container keyed by the provided key values.