Class: QgsExpressionNodeUnaryOperator

A unary node is either negative as in boolean (not) or as in numbers (minus).

Note

This is an abstract class, with methods which must be implemented by a subclass.

The following methods must be implemented: QgsExpressionNode.needsGeometry()

Class Hierarchy

Base classes

QgsExpressionNode

Abstract base class for all nodes that can appear in an expression.

Methods

op	Returns the unary operator.
operand	Returns the node the operator will operate upon.
text	Returns a the name of this operator without the operands.

Virtual Methods

In PyQGIS, only methods marked as virtual can be safely overridden in a Python subclass of QgsExpressionNodeUnaryOperator. See the FAQ for more details.

evalNode
prepareNode

Attributes

uoMinus
uoNot

class qgis.core.QgsExpressionNodeUnaryOperator

Bases: QgsExpressionNode

__init__(op: QgsExpressionNodeUnaryOperator.UnaryOperator, operand: QgsExpressionNode | None)

A node unary operator is modifying the value of operand by negating it with op.

Parameters:

• op (QgsExpressionNodeUnaryOperator.UnaryOperator)

• operand (Optional[QgsExpressionNode])

class UnaryOperator

Bases: int

virtual evalNode(self, parent: QgsExpression | None, context: QgsExpressionContext | None) → Any

Parameters:

• parent (Optional[QgsExpression])

• context (Optional[QgsExpressionContext])

Return type:

Any

op(self) → QgsExpressionNodeUnaryOperator.UnaryOperator

Returns the unary operator.

Return type:

QgsExpressionNodeUnaryOperator.UnaryOperator

operand(self) → QgsExpressionNode | None

Returns the node the operator will operate upon.

Return type:

Optional[QgsExpressionNode]

virtual prepareNode(self, parent: QgsExpression | None, context: QgsExpressionContext | None) → bool

Parameters:

• parent (Optional[QgsExpression])

• context (Optional[QgsExpressionContext])

Return type:

bool

text(self) → str

Returns a the name of this operator without the operands. I.e. “NOT” or “-”

Return type:

str

uoMinus = 1

uoNot = 0