Class: QgsProcessingParameterExpression

class qgis.core.QgsProcessingParameterExpression(name: str, description: str = '', defaultValue: Any = None, parentLayerParameterName: str = '', optional: bool = False)

Bases: QgsProcessingParameterDefinition

Constructor for QgsProcessingParameterExpression.

QgsProcessingParameterExpression(QgsProcessingParameterExpression)

An expression parameter for processing algorithms.

New in version 3.0.

Parameters
  • name (str) –

  • description (str = '') –

  • defaultValue (Any = None) –

  • parentLayerParameterName (str = '') –

  • optional

asPythonString(self, outputType: QgsProcessing.PythonOutputType = QgsProcessing.PythonQgsProcessingAlgorithmSubclass) → str
Parameters

outputType (QgsProcessing.PythonOutputType = QgsProcessing.PythonQgsProcessingAlgorithmSubclass) –

Return type

str

clone(self)QgsProcessingParameterDefinition
Return type

QgsProcessingParameterDefinition

dependsOnOtherParameters(self) → List[str]
Return type

List[str]

fromScriptCode(name: str, description: str, isOptional: bool, definition: str)QgsProcessingParameterExpression

Creates a new parameter using the definition from a script code.

Parameters
  • name (str) –

  • description (str) –

  • isOptional (bool) –

  • definition (str) –

Return type

QgsProcessingParameterExpression

fromVariantMap(self, map: Dict[str, Any]) → bool
Parameters

map (Dict[str) –

Return type

bool

parentLayerParameterName(self) → str

Returns the name of the parent layer parameter, or an empty string if this is not set.

Return type

str

setParentLayerParameterName(self, parentLayerParameterName: str)

Sets the name of the parent layer parameter. Use an empty string if this is not required.

Parameters

parentLayerParameterName (str) –

toVariantMap(self) → Dict[str, Any]
Return type

Dict[str, Any]

type(self) → str
Return type

str

typeName() → str

Returns the type name for the parameter class.

Return type

str

valueAsPythonString(self, value: Any, context: QgsProcessingContext) → str
Parameters
Return type

str