Class: QgsGeometryCollection

class qgis.core.QgsGeometryCollection

Bases: QgsAbstractGeometry

Geometry collection

QgsGeometryCollection() Constructor for an empty geometry collection.

QgsGeometryCollection(c: QgsGeometryCollection)

Methods

addGeometry	Adds a geometry and takes ownership.
addMValue	param mValue:
addZValue	param zValue:
adjacentVertices	param vertex:
area	rtype: float
asGml2	param doc:
asGml3	param doc:
asKml	param precision:
asQPainterPath	rtype: QPainterPath
asWkb	param flags:
asWkt	param precision:
boundary	rtype: QgsAbstractGeometry
boundingBox3D	rtype: QgsBox3D
boundingBoxIntersects	param box3d:
calculateBoundingBox	Default calculator for the minimal bounding box for the geometry.
calculateBoundingBox3D	rtype: QgsBox3D
childCount	rtype: int
childGeometry	param index:
childPoint	Returns point at index (for geometries without child geometries - i.e. curve / point).
clear
clearCache
clone	rtype: QgsGeometryCollection
closestSegment	param pt:
compareToSameClass	param other:
coordinateSequence	rtype: object
createEmptyWithSameType	rtype: QgsGeometryCollection
deleteVertex	param position:
dimension	rtype: int
draw	param p:
dropMValue	rtype: bool
dropZValue	rtype: bool
extractPartsByType	Returns a new QgsGeometryCollection subclass which consists of the parts of this collection which match the specified WKB type.
fromCollectionWkt	Reads a collection from a WKT string.
fromWkb	param wkb:
fromWkt	param wkt:
fuzzyDistanceEqual	param other:
fuzzyEqual	param other:
geometryN	Returns a geometry from within the collection.
geometryType	rtype: str
hasChildGeometries	Returns whether the geometry has any child geometries (False for point / curve, True otherwise)
hasCurvedSegments	rtype: bool
insertGeometry	Inserts a geometry before a specified index and takes ownership.
insertVertex	param position:
isEmpty	rtype: bool
isValid	param flags:
length	rtype: float
moveVertex	param position:
nCoordinates	rtype: int
nextVertex	param id:
normalize
numGeometries	Returns the number of geometries within the collection.
partCount	rtype: int
perimeter	rtype: float
removeDuplicateNodes	param epsilon:
removeGeometry	Removes a geometry from the collection by index.
reserve	Attempts to allocate memory for at least size geometries.
ringCount	param part:
segmentLength	param startVertex:
segmentize	Returns a geometry without curves.
setZMTypeFromSubGeometry	Updates the geometry type based on whether sub geometries contain z or m values.
simplifiedTypeRef	rtype: QgsAbstractGeometry
snappedToGrid	param hSpacing:
sortIndex	Returns the sort index for the geometry, used in the compareTo() method to compare geometries of different types.
swapXy
toCurveType	rtype: QgsGeometryCollection
transform	param ct:
vertexAngle	param vertex:
vertexAt	param id:
vertexCount	param part:
vertexNumberFromVertexId	param id:
wkbSize	param flags:
wktOmitChildType	Returns whether child type names are omitted from Wkt representations of the collection

addGeometry(self, g: QgsAbstractGeometry) → bool

Adds a geometry and takes ownership. Returns True in case of success.

Parameters:

g (QgsAbstractGeometry)

Return type:

bool

addMValue(self, mValue: float = 0) → bool

Parameters:

mValue (float = 0)

Return type:

bool

addZValue(self, zValue: float = 0) → bool

Parameters:

zValue (float = 0)

Return type:

bool

adjacentVertices(self, vertex: QgsVertexId) → Tuple[QgsVertexId, QgsVertexId]

Parameters:

vertex (QgsVertexId)

Return type:

Tuple[QgsVertexId, QgsVertexId]

area(self) → float

Return type:

float

asGml2(self, doc: QDomDocument, precision: int = 17, ns: str = '', axisOrder: QgsAbstractGeometry.AxisOrder = QgsAbstractGeometry.AxisOrder.XY) → QDomElement

Parameters:

• doc (QDomDocument)

• precision (int = 17)

• ns (str = '')

• axisOrder (QgsAbstractGeometry.AxisOrder = QgsAbstractGeometry.AxisOrder.XY)

Return type:

QDomElement

asGml3(self, doc: QDomDocument, precision: int = 17, ns: str = '', axisOrder: QgsAbstractGeometry.AxisOrder = QgsAbstractGeometry.AxisOrder.XY) → QDomElement

Parameters:

• doc (QDomDocument)

• precision (int = 17)

• ns (str = '')

• axisOrder (QgsAbstractGeometry.AxisOrder = QgsAbstractGeometry.AxisOrder.XY)

Return type:

QDomElement

asKml(self, precision: int = 17) → str

Parameters:

precision (int = 17)

Return type:

str

asQPainterPath(self) → QPainterPath

Return type:

QPainterPath

asWkb(self, flags: QgsAbstractGeometry.WkbFlags | QgsAbstractGeometry.WkbFlag = QgsAbstractGeometry.WkbFlags()) → QByteArray

Parameters:

flags (Union[QgsAbstractGeometry.WkbFlags)

Return type:

QByteArray

asWkt(self, precision: int = 17) → str

Parameters:

precision (int = 17)

Return type:

str

boundary(self) → QgsAbstractGeometry

Return type:

QgsAbstractGeometry

boundingBox3D(self) → QgsBox3D

Return type:

QgsBox3D

boundingBoxIntersects(self, box3d: QgsBox3D) → bool

Parameters:

box3d (QgsBox3D)

Return type:

bool

calculateBoundingBox(self) → QgsRectangle

Default calculator for the minimal bounding box for the geometry. Derived classes should override this method if a more efficient bounding box calculation is available.

calculateBoundingBox3D(self) → QgsBox3D

Return type:

QgsBox3D

childCount(self) → int

Return type:

int

childGeometry(self, index: int) → QgsAbstractGeometry

Parameters:

index (int)

Return type:

QgsAbstractGeometry

childPoint(self, index: int) → QgsPoint

Returns point at index (for geometries without child geometries - i.e. curve / point)

Note

used for vertex_iterator implementation

clear(self)

clearCache(self)

clone(self) → QgsGeometryCollection

Return type:

QgsGeometryCollection

closestSegment(self, pt: QgsPoint, epsilon: float = 4 * DBL_EPSILON) → Tuple[float, QgsPoint, QgsVertexId, int]

Parameters:

• pt (QgsPoint)

• epsilon (float = 4*DBL_EPSILON)

Return type:

Tuple[float, QgsPoint, QgsVertexId, int]

compareToSameClass(self, other: QgsAbstractGeometry) → int

Parameters:

other (QgsAbstractGeometry)

Return type:

int

coordinateSequence(self) → object

Return type:

object

createEmptyWithSameType(self) → QgsGeometryCollection

Return type:

QgsGeometryCollection

deleteVertex(self, position: QgsVertexId) → bool

Parameters:

position (QgsVertexId)

Return type:

bool

dimension(self) → int

Return type:

int

draw(self, p: QPainter)

Parameters:

p (QPainter)

dropMValue(self) → bool

Return type:

bool

dropZValue(self) → bool

Return type:

bool

extractPartsByType(self, type: Qgis.WkbType, useFlatType: bool = True) → QgsGeometryCollection

Returns a new QgsGeometryCollection subclass which consists of the parts of this collection which match the specified WKB type.

For instance, if type is Qgis.WkbType.Polygon, then the returned object will be a QgsMultiPolygon object containing just the polygons from this collection.

If useFlatType is True, then the WKB types of component geometries from this collection will be flattened prior to comparing with type. (I.e. the presence of Z / M dimensions will be ignored when comparing against type).

Added in version 3.36.

Parameters:

• type (Qgis.WkbType)

• useFlatType (bool = True)

Return type:

QgsGeometryCollection

fromCollectionWkt(self, wkt: str, subtypes: Iterable[QgsAbstractGeometry], defaultChildWkbType: str = '') → bool

Reads a collection from a WKT string.

Parameters:

• wkt (str)

• subtypes (Iterable[QgsAbstractGeometry])

• defaultChildWkbType (str = '')

Return type:

bool

fromWkb(self, wkb: QgsConstWkbPtr) → bool

Parameters:

wkb (QgsConstWkbPtr)

Return type:

bool

fromWkt(self, wkt: str) → bool

Parameters:

wkt (str)

Return type:

bool

fuzzyDistanceEqual(self, other: QgsAbstractGeometry, epsilon: float = 1e-08) → bool

Parameters:

• other (QgsAbstractGeometry)

• epsilon (float = 1e-08)

Return type:

bool

fuzzyEqual(self, other: QgsAbstractGeometry, epsilon: float = 1e-08) → bool

Parameters:

• other (QgsAbstractGeometry)

• epsilon (float = 1e-08)

Return type:

bool

geometryN(self, n: int) → QgsAbstractGeometry

Returns a geometry from within the collection.

Parameters:

n (int) – index of geometry to return.

Raises:

IndexError – if no geometry with the specified index exists.

Return type:

QgsAbstractGeometry

geometryType(self) → str

Return type:

str

hasChildGeometries(self) → bool

Returns whether the geometry has any child geometries (False for point / curve, True otherwise)

Note

used for vertex_iterator implementation

hasCurvedSegments(self) → bool

Return type:

bool

insertGeometry(self, g: QgsAbstractGeometry, index: int) → bool

Inserts a geometry before a specified index and takes ownership. Returns True in case of success.

Parameters:

• g (QgsAbstractGeometry) – geometry to insert. Ownership is transferred to the collection.

• index (int) – position to insert geometry before

Return type:

bool

insertVertex(self, position: QgsVertexId, vertex: QgsPoint) → bool

Parameters:

• position (QgsVertexId)

• vertex (QgsPoint)

Return type:

bool

isEmpty(self) → bool

Return type:

bool

isValid(self, flags: Qgis.GeometryValidityFlags | Qgis.GeometryValidityFlag = Qgis.GeometryValidityFlags()) → Tuple[bool, str]

Parameters:

flags (Union[Qgis.GeometryValidityFlags)

Return type:

Tuple[bool, str]

length(self) → float

Return type:

float

moveVertex(self, position: QgsVertexId, newPos: QgsPoint) → bool

Parameters:

• position (QgsVertexId)

• newPos (QgsPoint)

Return type:

bool

nCoordinates(self) → int

Return type:

int

nextVertex(self, id: QgsVertexId) → Tuple[bool, QgsPoint]

Parameters:

id (QgsVertexId)

Return type:

Tuple[bool, QgsPoint]

normalize(self)

numGeometries(self) → int

Returns the number of geometries within the collection.

Return type:

int

partCount(self) → int

Return type:

int

perimeter(self) → float

Return type:

float

removeDuplicateNodes(self, epsilon: float = 4 * DBL_EPSILON, useZValues: bool = False) → bool

Parameters:

• epsilon (float = 4*DBL_EPSILON)

• useZValues (bool = False)

Return type:

bool

removeGeometry(self, nr: int) → bool

Removes a geometry from the collection by index.

Return type:

bool

Returns:

True if removal was successful.

Raises:

IndexError – if no geometry with the specified index exists.

Parameters:

nr (int)

reserve(self, size: int)

Attempts to allocate memory for at least size geometries.

If the number of geometries is known in advance, calling this function prior to adding geometries will prevent reallocations and memory fragmentation.

Added in version 3.10.

Parameters:

size (int)

ringCount(self, part: int = 0) → int

Parameters:

part (int = 0)

Return type:

int

segmentLength(self, startVertex: QgsVertexId) → float

Parameters:

startVertex (QgsVertexId)

Return type:

float

segmentize(self, tolerance: float = M_PI_2 / 90, toleranceType: QgsAbstractGeometry.SegmentationToleranceType = QgsAbstractGeometry.MaximumAngle) → QgsAbstractGeometry

Returns a geometry without curves. Caller takes ownership

Parameters:

• tolerance (float = M_PI_2/90) – segmentation tolerance

• toleranceType (QgsAbstractGeometry.SegmentationToleranceType = QgsAbstractGeometry.MaximumAngle) – maximum segmentation angle or maximum difference between approximation and curve

Return type:

QgsAbstractGeometry

setZMTypeFromSubGeometry(self, subggeom: QgsAbstractGeometry, baseGeomType: Qgis.WkbType)

Updates the geometry type based on whether sub geometries contain z or m values.

simplifiedTypeRef(self) → QgsAbstractGeometry

Return type:

QgsAbstractGeometry

snappedToGrid(self, hSpacing: float, vSpacing: float, dSpacing: float = 0, mSpacing: float = 0) → QgsGeometryCollection

Parameters:

• hSpacing (float)

• vSpacing (float)

• dSpacing (float = 0)

• mSpacing (float = 0)

Return type:

QgsGeometryCollection

sortIndex(self) → int

Returns the sort index for the geometry, used in the compareTo() method to compare geometries of different types.

Added in version 3.20.

swapXy(self)

toCurveType(self) → QgsGeometryCollection

Return type:

QgsGeometryCollection

transform(self, ct: QgsCoordinateTransform, d: Qgis.TransformDirection = Qgis.TransformDirection.Forward, transformZ: bool = False)

transform(self, t: QTransform, zTranslate: float = 0, zScale: float = 1, mTranslate: float = 0, mScale: float = 1) → None

transform(self, transformer: QgsAbstractGeometryTransformer, feedback: QgsFeedback = None) → bool

Parameters:

• ct (QgsCoordinateTransform)

• d (Qgis.TransformDirection = Qgis.TransformDirection.Forward)

• transformZ (bool = False)

vertexAngle(self, vertex: QgsVertexId) → float

Parameters:

vertex (QgsVertexId)

Return type:

float

vertexAt(self, id: QgsVertexId) → QgsPoint

Parameters:

id (QgsVertexId)

Return type:

QgsPoint

vertexCount(self, part: int = 0, ring: int = 0) → int

Parameters:

• part (int = 0)

• ring (int = 0)

Return type:

int

vertexNumberFromVertexId(self, id: QgsVertexId) → int

Parameters:

id (QgsVertexId)

Return type:

int

wkbSize(self, flags: QgsAbstractGeometry.WkbFlags | QgsAbstractGeometry.WkbFlag = QgsAbstractGeometry.WkbFlags()) → int

Parameters:

flags (Union[QgsAbstractGeometry.WkbFlags)

Return type:

int

wktOmitChildType(self) → bool

Returns whether child type names are omitted from Wkt representations of the collection

Return type:

bool