QQuantity

A widget that allows the user to edit a quantity (a magnitude associated with a unit).

Note

This widget requires pint:

pip install pint

or

pip install superqt[quantity]

from qtpy.QtWidgets import QApplication

from superqt import QQuantity

app = QApplication([])
w = QQuantity("1m")
w.show()

app.exec()

Qt Class

QWidget

Signals

dimensionalityChanged

valueChanged

unitsChanged

Methods

A combination QDoubleSpinBox and QComboBox for entering quantities.

For this widget, value() returns a pint.Quantity object, while setValue() accepts either a number, pint.Quantity, a string that can be parsed by pint.

Parameters:

Name	Type	Description	Default
value	Union[str, Quantity, Number]	The initial value to display. If a string, it will be parsed by pint.	0
units	Union[UnitsContainer, str, Quantity]	The units to use if value is a number. If a string, it will be parsed by pint. If a pint.Quantity, the units will be extracted from it.	None
ureg	UnitRegistry	The unit registry to use. If not provided, the registry will be extracted from value if it is a pint.Quantity, otherwise the default registry will be used.	None
parent	QWidget	The parent widget, by default None	None

dimensionality() -> UnitsContainer

Return the current dimensionality (cast to str for nice repr).

isDimensionless() -> bool

Return True if the current value is dimensionless.

magnitude() -> Union[float, int]

Return the magnitude of the current value.

magnitudeSpinBox() -> QDoubleSpinBox

Return the QSpinBox widget used to edit the magnitude.

setDecimals(decimals: int) -> None

Set the number of decimals to display in the spinbox.

setMagnitude(magnitude: Number) -> None

Set the magnitude of the current value.

setUnits(units: Union[str, Unit, Quantity]) -> None

Set the units of the current value.

If units is None, will convert to a dimensionless quantity. Otherwise, units must be compatible with the current dimensionality.

setValue(value: Union[str, Quantity, Number], units: Optional[Union[UnitsContainer, str, Quantity]] = None) -> None

Set the current value (will cast to a pint Quantity).

text() -> str

unitRegistry() -> UnitRegistry

Return the pint UnitRegistry used by this widget.

units() -> Unit

Return the current units.

unitsComboBox() -> QComboBox

Return the QCombBox widget used to edit the units.

value() -> Quantity

Return the current value as a pint.Quantity.