Layers

qgis_project.Layer(file, crs=None, visible=True, group=None, name=None, overwrite_existing=False, style=None, filter=None, min_scale=None, max_scale=None, labels=None) dataclass

Bases: _LayerMixin

A local file-based layer (vector or raster).

Parameters:

Name	Type	Description	Default
file	str	Path to the layer file (".shp", ".geojson", ".gpkg", ".tif", ".tiff", ".img", ".nc").	required
crs	str or int or None	Override the layer CRS. Accepts an EPSG integer or authority string (e.g. "EPSG:4326"). If None, the layer's native CRS is used.	None
visible	bool	Whether the layer is visible when the project opens.	True
group	str or list of str or None	Layer group path. A plain string places the layer in a top-level group; a list creates a nested hierarchy, e.g. ["terrain", "raw"].	None
name	str or None	Display name in the layer tree. Defaults to the file's basename.	None
overwrite_existing	bool	If True, replace an existing layer at the same group path; if False (default), skip silently.	False
style	VectorStyle or None	Vector styling to apply (e.g. VectorStyleSingleSymbol, VectorStyleCategorized, VectorStyleGraduated). If None, the QGIS default symbol is used. Ignored for raster files.	None
filter	str or None	QGIS expression used as a subset filter (QgsVectorLayer.setSubsetString), e.g. "population > 1000". Only the matching features are loaded, rendered, and included in extent/statistics calculations. Ignored for raster files.	None
min_scale	float or None	Most zoomed-out scale denominator at which the layer is still visible, e.g. 100000 for 1:100,000. Zooming out further (larger denominator) hides the layer. If None, no zoomed-out limit.	None
max_scale	float or None	Most zoomed-in scale denominator at which the layer is still visible, e.g. 1000 for 1:1,000. Zooming in further (smaller denominator) hides the layer. If None, no zoomed-in limit.	None
labels	VectorLabels or None	Attribute-based labels to show on the layer. Independent of style. Ignored for raster files.	None

get_layer_name()

Get the dataset's name as shown in the layer.

Source code in qgis_project/layer.py

def get_layer_name(self):
    """Get the dataset's name as shown in the layer."""
    return self.name or os.path.basename(self.file)

qgis_project.RasterLayer(file, crs=None, visible=True, group=None, name=None, overwrite_existing=False, style=RasterStyle(), filter=None, min_scale=None, max_scale=None, labels=None, band_idx=1, variable=None, statistics_kwargs=dict()) dataclass

Bases: Layer

qgis_project.WebLayer(uri, provider='wms', name='', group=None, visible=True, crs=None, overwrite_existing=False) dataclass

Bases: _LayerMixin

A layer sourced from a web service (XYZ tiles, WMS, WFS, etc.).

Prefer the factory class methods over constructing directly: WebLayer.osm() WebLayer.xyz(url) WebLayer.wms(url, layers) WebLayer.wfs(url, typename)

osm(**kwargs) classmethod

OpenStreetMap tile layer.

Source code in qgis_project/layer.py

@classmethod
def osm(cls, **kwargs) -> "WebLayer":
    """OpenStreetMap tile layer."""
    kwargs.setdefault("name", "OpenStreetMap")
    return cls.xyz("https://tile.openstreetmap.org/{z}/{x}/{y}.png", **kwargs)

wfs(url, typename, name='', **kwargs) classmethod

OGC Web Feature Service layer.

Source code in qgis_project/layer.py

@classmethod
def wfs(cls, url: str, typename: str, name: str = "", **kwargs) -> "WebLayer":
    """OGC Web Feature Service layer."""
    uri = f"url={url}&typename={typename}&version=auto"
    return cls(uri=uri, provider="WFS", name=name or typename, **kwargs)

wms(url, layers, format='image/png', crs='EPSG:4326', name='', **kwargs) classmethod

OGC Web Map Service layer.

Source code in qgis_project/layer.py

@classmethod
def wms(
    cls,
    url: str,
    layers: str,
    format: str = "image/png",
    crs: str = "EPSG:4326",
    name: str = "",
    **kwargs,
) -> "WebLayer":
    """OGC Web Map Service layer."""
    uri = f"url={url}&layers={layers}&styles=&format={format}&crs={crs}"
    return cls(uri=uri, provider="wms", name=name or layers, crs=crs, **kwargs)

xyz(url, name='XYZ', zmin=0, zmax=19, **kwargs) classmethod

XYZ/slippy-map tile layer.

Source code in qgis_project/layer.py

@classmethod
def xyz(
    cls, url: str, name: str = "XYZ", zmin: int = 0, zmax: int = 19, **kwargs
) -> "WebLayer":
    """XYZ/slippy-map tile layer."""
    uri = f"type=xyz&url={url}&zmin={zmin}&zmax={zmax}"
    return cls(uri=uri, provider="wms", name=name, **kwargs)

qgis_project.ProcessingOp(algorithm, params, name='', group=None, visible=True) dataclass

A QGIS Processing algorithm to run, whose result is added to the project as a layer.

Parameters:

Name	Type	Description	Default
algorithm	str	QGIS processing algorithm identifier, e.g. "native:buffer".	required
params	dict	Algorithm parameters passed directly to processing.run(). Must include "INPUT" and, for most algorithms, "OUTPUT". Set "OUTPUT" to "memory:" for an in-memory vector result, or a file path (e.g. "/tmp/out.gpkg") for a persistent output.	required
name	str	Name for the result layer in the layer tree. Defaults to the algorithm identifier tail (e.g. "buffer").	''
group	str or list of str or None	Layer group path, same syntax as :class:Layer.	None
visible	bool	Whether the result layer is visible when the project opens.	True