Class: QgsRasterAttributeTable

Represents a Raster Attribute Table (RAT).

This class is modeled after the GDAL Raster Attribute Table implementation, it adds some convenience methods to handle data from QGIS and to import/export a Raster Attribute Table from/to a DBF VAT file.

Added in version 3.30.

class qgis.core.QgsRasterAttributeTable[source]

Bases: object

class Field[source]

Bases: object

The Field class represents a Raster Attribute Table field, including its name, usage and type.

Added in version 3.30.

QgsRasterAttributeTable.Field(name: Optional[str], usage: Qgis.RasterAttributeTableFieldUsage, type: QMetaType.Type) Creates a new Field with name, type and usage.

QgsRasterAttributeTable.Field(name: Optional[str], usage: Qgis.RasterAttributeTableFieldUsage, type: QVariant.Type) Creates a new Field with name, type and usage.

Deprecated since version 3.38: Use the method with a QMetaType.Type argument instead.

QgsRasterAttributeTable.Field(a0: QgsRasterAttributeTable.Field)

isColor(self) → bool[source]

Returns True if the field carries a color component (Red, Green, Blue and optionally Alpha) information.

Return type:

bool

isRamp(self) → bool[source]

Returns True if the field carries a color ramp component information (RedMin/RedMax, GreenMin/GreenMax, BlueMin/BlueMax and optionally AlphaMin/AlphaMax) information.

Return type:

bool

name
type
usage
class MinMaxClass[source]

Bases: object

The Field class represents a Raster Attribute Table classification entry for a thematic Raster Attribute Table.

Added in version 3.30.

color
minMaxValues: List[float]
name
class UsageInformation[source]

Bases: object

The UsageInformation class represents information about a field usage.

Added in version 3.30.

allowedTypes: List[QMetaType.Type]
description: str
isColor: bool
isRamp: bool
maybeClass: bool
required: bool
supported: bool
unique: bool
appendField(self, name: str | None, usage: Qgis.RasterAttributeTableFieldUsage, type: QMetaType.Type)[source]

Creates a new field from name, usage and type and appends it to the fields, optionally reporting any error in errorMessage, returns True on success.

appendField(self, name: Optional[str], usage: Qgis.RasterAttributeTableFieldUsage, type: QVariant.Type) -> (bool, Optional[str]) Creates a new field from name, usage and type and appends it to the fields, optionally reporting any error in errorMessage, returns True on success.

appendField(self, field: QgsRasterAttributeTable.Field) -> (bool, Optional[str]) Appends a new field, optionally reporting any error in errorMessage, returns True on success.

Parameters:
appendRow(self, data: Iterable[Any])[source]

Appends a row of data to the RAT, optionally reporting any error in errorMessage, returns True on success.

Parameters:

data (Iterable[Any]) -> (bool)

color(self, row: int) → QColor[source]

Returns the color of the rat row or an invalid color if row does not exist or if there is no color definition.

See also

hasColor()

See also

setColor()

See also

hasRamp()

See also

setRamp()

See also

ramp()

Parameters:

row (int)

Return type:

QColor

colorRamp(self, labelColumn: int = -1)[source]

Returns the color ramp for an athematic Raster Attribute Table setting the labels in labels, optionally generated from labelColumn.

Parameters:

labelColumn (int = -1) -> (QgsGradientColorRamp)

static createFromRaster(rasterLayer: QgsRasterLayer | None)[source]

Creates a new Raster Attribute Table from a raster layer, the renderer must be Paletted or SingleBandPseudoColor, optionally reporting the raster band from which the attribute table was created.

Parameters:

rasterLayer (Optional[QgsRasterLayer]) -> (Optional[QgsRasterAttributeTable]) – raster layer

Returns:

  • None in case of errors or unsupported renderer.

  • bandNumber: band number

createRenderer(self, provider: QgsRasterDataProvider | None, bandNumber: int, classificationColumn: int = -1) → QgsRasterRenderer | None[source]

Creates and returns a (possibly None) raster renderer for the specified provider and bandNumber and optionally reclassified by classificationColumn, the default value of -1 makes the method guess the classification column based on the field usage.

Note

athematic attribute tables with color ramps cannot be reclassified, the renderer will still use the classificationColumn for generating the class labels.

Parameters:
Return type:

Optional[QgsRasterRenderer]

data(self) → Any

Returns the Raster Attribute Table rows.

Return type:

Any

fieldByName(self, name: str | None)[source]

Returns a field by name or a default constructed field with empty name if the field is not found.

Parameters:

name (Optional[str]) -> (QgsRasterAttributeTable.Field) – of the field

Returns:

  • the matching field or a default constructed one.

  • ok: True if the field was found.

fields(self) → List[QgsRasterAttributeTable.Field]

Returns the Raster Attribute Table fields.

See also

qgisFields()

Return type:

List[QgsRasterAttributeTable.Field]

fieldsByUsage(self, fieldUsage: Qgis.RasterAttributeTableFieldUsage) → List[QgsRasterAttributeTable.Field]

Returns the list of fields matching fieldUsage.

Parameters:

fieldUsage (Qgis.RasterAttributeTableFieldUsage)

Return type:

List[QgsRasterAttributeTable.Field]

filePath(self) → str[source]

Returns the (possibly empty) path of the file-based RAT, the path is set when a RAT is read or written from/to a file.

See also

writeToFile()

See also

readFromFile()

Return type:

str

static guessFieldUsage(name: str | None, type: QMetaType.Type) → Qgis.RasterAttributeTableFieldUsage[source]

Try to determine the field usage from its name and type.

guessFieldUsage(name: Optional[str], type: QVariant.Type) -> Qgis.RasterAttributeTableFieldUsage Try to determine the field usage from its name and type.

Parameters:

  • name (Optional[str])

  • type (QMetaType.Type)

Return type:

Qgis.RasterAttributeTableFieldUsage

hasColor(self) → bool[source]

Returns True if the Raster Attribute Table has color RGBA information.

See also

color()

See also

setColor()

See also

hasRamp()

See also

setRamp()

See also

ramp()

Return type:

bool

hasRamp(self) → bool[source]

Returns True if the Raster Attribute Table has ramp RGBA information.

See also

setRamp()

See also

ramp()

See also

hasColor()

See also

setColor()

Return type:

bool

insertColor(self, position: int)[source]

Create RGBA fields and inserts them at position, optionally reporting any error in errorMessage, returns True on success.

Parameters:

position (int) -> (bool)

insertField(self, position: int, field: QgsRasterAttributeTable.Field)[source]

Inserts a new field at position, optionally reporting any error in errorMessage, returns True on success.

Note

Out of range position is automatically clamped to a valid value.

insertField(self, position: int, name: Optional[str], usage: Qgis.RasterAttributeTableFieldUsage, type: QMetaType.Type) -> (bool, Optional[str]) Creates a new field from name, usage and type and inserts it at position, optionally reporting any error in errorMessage, returns True on success.

insertField(self, position: int, name: Optional[str], usage: Qgis.RasterAttributeTableFieldUsage, type: QVariant.Type) -> (bool, Optional[str]) Creates a new field from name, usage and type and inserts it at position, optionally reporting any error in errorMessage, returns True on success.

Deprecated since version 3.38: Use the method with a QMetaType.Type argument instead.

Parameters:
insertRamp(self, position: int)[source]

Create RGBA minimum and maximum fields and inserts them at position, optionally reporting any error in errorMessage, returns True on success.

Parameters:

position (int) -> (bool)

insertRow(self, position: int, rowData: Iterable[Any])[source]

Inserts a row of rowData in the Raster Attribute Table at position, optionally reporting any error in errorMessage, returns True on success.

Note

Out of range position is automatically clamped to a valid value.

Parameters:

  • position (int)

  • rowData (Iterable[Any]) -> (bool)

isDirty(self) → bool[source]

Returns True if the Raster Attribute Table was modified from its last reading from the storage.

Return type:

bool

isValid(self)[source]

Returns True if the Raster Attribute Table is valid, optionally reporting validity checks results in errorMessage.

maximumValue(self) → float[source]

Returns the maximum value of the MinMax (thematic) or Max (athematic) column, returns NaN on errors.

Return type:

float

minMaxClasses(self, classificationColumn: int = -1) → List[QgsRasterAttributeTable.MinMaxClass]

Returns the classes for a thematic Raster Attribute Table, classified by classificationColumn, the default value of -1 makes the method guess the classification column based on the field usage.

Parameters:

classificationColumn (int = -1)

Return type:

List[QgsRasterAttributeTable.MinMaxClass]

minimumValue(self) → float[source]

Returns the minimum value of the MinMax (thematic) or Min (athematic) column, returns NaN on errors.

Return type:

float

orderedRows(self) → Any

Returns the data rows ordered by the value column(s) in ascending order, if the attribute table type is athematic the middle value for each row range is considered for ordering. If the attribute table does not have any value field (and hence is not valid), the current data are returned without any change.

Return type:

Any

qgisFeatures(self) → List[QgsFeature][source]

Returns the Raster Attribute Table rows as a list of QgsFeature.

Return type:

List[QgsFeature]

qgisFields(self) → QgsFields[source]

Returns the Raster Attribute Table fields as QgsFields.

See also

fields()

Return type:

QgsFields

ramp(self, row: int) → QgsGradientColorRamp[source]

Returns the gradient color ramp of the rat row or a default constructed gradient if row does not exist or if there is no color ramp definition.

See also

hasRamp()

See also

setRamp()

See also

hasColor()

See also

setColor()

See also

color()

Parameters:

row (int)

Return type:

QgsGradientColorRamp

readFromFile(self, path: str | None)[source]

Reads the Raster Attribute Table from a DBF file specified by path, optionally reporting any error in errorMessage, returns True on success.

Parameters:

path (Optional[str]) -> (bool)

removeField(self, name: str | None)[source]

Removes the field with name, optionally reporting any error in errorMessage, returns True on success.

Parameters:

name (Optional[str]) -> (bool)

removeRow(self, position: int = 0)[source]

Removes the row in the Raster Attribute Table at position, optionally reporting any error in errorMessage, returns True on success.

Note

position must be a valid position.

Parameters:

position (int = 0) -> (bool)

row(self, matchValue: float) → List[Any][source]

Returns a row of data for the given matchValue or and empty row if there is not match.

Parameters:

matchValue (float)

Return type:

List[Any]

setColor(self, row: int, color: QColor | Qt.GlobalColor) → bool[source]

Sets the color for the row at rowIndex to color. returns True on success.

See also

hasColor()

See also

setColor()

See also

hasRamp()

See also

setRamp()

See also

ramp()

Parameters:

  • row (int)

  • color (Union[QColor, Qt.GlobalColor])

Return type:

bool

setDirty(self, isDirty: bool)[source]

Sets the Raster Attribute Table dirty state to isDirty;

Parameters:

isDirty (bool)

setFieldUsage(self, fieldIndex: int, usage: Qgis.RasterAttributeTableFieldUsage) → bool[source]

Change the usage of the field at index fieldIndex to usage with checks for allowed types.

Return type:

bool

Returns:

True on success.

Parameters:
setRamp(self, row: int, colorMin: QColor | Qt.GlobalColor, colorMax: QColor | Qt.GlobalColor) → bool[source]

Sets the color ramp for the row at rowIndex to colorMin and colorMax. returns True on success.

See also

hasRamp()

See also

ramp()

See also

hasColor()

See also

setColor()

Parameters:

  • row (int)

  • colorMin (Union[QColor, Qt.GlobalColor])

  • colorMax (Union[QColor, Qt.GlobalColor])

Return type:

bool

setValue(self, row: int, column: int, value: Any) → bool[source]

Sets the value for row and column.

Return type:

bool

Returns:

True on success.

Parameters:

  • row (int)

  • column (int)

  • value (Any)

type(self) → Qgis.RasterAttributeTableType[source]

Returns the Raster Attribute Table type.

Return type:

Qgis.RasterAttributeTableType

static usageInformation() → Dict[int, QgsRasterAttributeTable.UsageInformation]

Returns information about supported Raster Attribute Table usages.

See also

usageName()

Return type:

Dict[int, QgsRasterAttributeTable.UsageInformation]

static usageName(fieldusage: Qgis.RasterAttributeTableFieldUsage) → str[source]

Returns the translated human readable name of fieldUsage.

See also

usageInformation()

Parameters:

fieldusage (Qgis.RasterAttributeTableFieldUsage)

Return type:

str

usages(self) → List[int]

Returns the list of field usages.

Return type:

List[int]

value(self, row: int, column: int) → Any[source]

Returns the value for row and column.

Parameters:

  • row (int)

  • column (int)

Return type:

Any

static valueAndColorFieldUsages() → List[Qgis.RasterAttributeTableFieldUsage]

Returns the list of field usages for colors and values.

Return type:

List[Qgis.RasterAttributeTableFieldUsage]

writeToFile(self, path: str | None)[source]

Writes the Raster Attribute Table to a DBF file specified by path, optionally reporting any error in errorMessage, returns True on success.

Note

“.vat.dbf” extension is automatically added to the file path if not present.

Parameters:

path (Optional[str]) -> (bool)