Parameters¶

Bases: CLI

Base class for script-style single models with parameters.

Declare parameters as class attributes in the same form as dataclass fields with any of:

• Standard type annotations (int, float, bool, etc.)
• Default value (unannotated attributes infer types from default values)
• Field factory functions provided for creating fields with constraints
• dataclasses.field same as any other dataclass

When run directly as a script, CLI arguments are parsed automatically at class definition time, and resolved parameter values are accessible as class attributes. A handler is registered to retrieve the rendered model using show when the script completes, if not manually called.

A presets class attribute may declare a selection of Preset objects.

class P(Params):
    width = Float(40.0, min=10, max=100)
    thickness = Float(3.0, min=1, max=10)

    presets = (Preset("small", width=15.0, thickness=2.0),)

result = Box(P.width, P.width, P.thickness)

with_preset(preset: str, **overrides: Any) -> Self

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@classmethod
def with_preset(cls, preset: str, **overrides: Any) -> Self:
    """Create a new instance with values from a preset applied.

    Args:
        preset: Name of the preset to apply.
        **overrides: Additional field values to apply after the preset.
    """
    return cls(preset=preset, **overrides)