Class: QgsArrowIterator¶
Wrapper for an Arrow reader of features from vector data provider or vector layer.
Added in version 4.0.
Methods
Build an ArrowArray using the next n features (or fewer depending on the number of features remaining) |
|
Set the ArrowSchema for the output of all future batches |
Static Methods
Infer the |
- class qgis.core.QgsArrowIterator[source]¶
Bases:
object- __init__()
Construct invalid iterator
- __init__(featureIterator: QgsFeatureIterator)
Construct iterator from an existing feature iterator
- Parameters:
featureIterator (QgsFeatureIterator)
- __init__(a0: QgsArrowIterator)
- Parameters:
a0 (QgsArrowIterator)
- static inferSchema(layer: QgsVectorLayer, options: QgsArrowInferSchemaOptions = QgsArrowInferSchemaOptions()) QgsArrowSchema[source]¶
Infer the
QgsArrowSchemafor a givenQgsVectorLayer- Raises:
QgsException – if one or more attribute fields is of an unsupported type.
- Parameters:
layer (
QgsVectorLayer)options (
QgsArrowInferSchemaOptions= QgsArrowInferSchemaOptions())
- Return type:
- static inferSchema(fields: QgsFields, hasGeometry: bool = False, crs: QgsCoordinateReferenceSystem = QgsCoordinateReferenceSystem(), options: QgsArrowInferSchemaOptions = QgsArrowInferSchemaOptions()) QgsArrowSchema[source]
Infer the
QgsArrowSchemafrom components- Raises:
QgsException – if one or more attribute fields is of an unsupported type.
- Parameters:
fields (
QgsFields)hasGeometry (bool = False)
crs (
QgsCoordinateReferenceSystem= QgsCoordinateReferenceSystem())options (
QgsArrowInferSchemaOptions= QgsArrowInferSchemaOptions())
- Return type:
- nextFeatures(self, n: int) QgsArrowArray[source]¶
Build an ArrowArray using the next n features (or fewer depending on the number of features remaining)
If no features remain, the returned array will be invalid (i.e.,
isValid()will returnFalse).- Raises:
QgsException – if a feature’s attribute cannot be appended to an ArrowArray of the requested type or on internal error when building the array.
- Parameters:
n (int)
- Return type:
- setSchema(self, schema: QgsArrowSchema)[source]¶
Set the ArrowSchema for the output of all future batches
This must be set before calling
nextFeatures().- Parameters:
schema (QgsArrowSchema)