Class: QgsExpressionNodeUnaryOperator

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

Class Hierarchy

Base classes

QgsExpressionNode

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

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])

__init__(a0: QgsExpressionNodeUnaryOperator)

Parameters:

a0 (QgsExpressionNodeUnaryOperator)

class UnaryOperator

Bases: int

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]

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