In this task we will use python scripting to buffer the features of a vector layer (using a buffer distance stored in a field) and save it as a memory layer. The Processing algorithm Variable distance buffer does the same thing, but we want to do it using Python. We can use the following code (if you don’t […]
Read more "How to buffer vectors (from fields) in QGIS using Python"In this task we will use python scripting to generate a vector grid of polygons (each one of them will have specific attributes) and save it as a memory layer. The Processing algorithm Vector grid does the same thing, but we want to do it using Python. We need some input parameters: the extent of the […]
Read more "How to generate a vector grid of polygons in QGIS using Python"In this task we will select all the shapefiles in a folder and use python scripting to merge them with their attributes in a memory layer. The Processing algorithm Merge vector layers does the same thing, but we want to do it using Python. The script is similar to that proposed in a previous task, but this […]
Read more "How to merge multiple vector layers in QGIS from a folder using Python"How to merge multiple vector layers from Layers Panel in QGIS using Python
Read more "How to merge multiple vector layers from Layers Panel in QGIS using Python"In this task we will see how to get the attributes of a vector layer and export them in a text file. Furthermore, at the end of the task we will order these attributes alphabetically before writing them in the output file. As a sample, we will use the vector layer that we have filtered in […]
Read more "How to export attributes from QGIS to a .txt file using Python"In this task we will see how to generate a vector grid of regularly spaced points. The Processing algorithm Regular points does the same thing, but we want to do it using Python. We assume to start from a layer that is already loaded in QGIS (if not, please see here) because we need to […]
Read more "How to generate regularly spaced points in QGIS using Python"In this task we will see how to load a layer in QGIS and add it to the map. All the operation are similar for both raster and vector layers. The first operation is to select the Python Console from the Plugins menu: Then, if you have to load a Vector layer: If you have to load a […]
Read more "How to load a layer in QGIS using Python"In this task we will load a vector layer representing some data about population and use python scripting to select all the cities with more than one million people. We will use a dataset from Natural Earth: download the population shapefile here. The data about city population are contained in the attribute “pop_max”, as you can see […]
Read more "How to select features in QGIS using Python"We’ll perform a spatial operation, using Python, to select all the points that intersect a polygon. Firstly, we need a point layer and a polygon layer: Method 1 Use this method if your layers are not already loaded in QGIS. Otherwise, directly skip to Method 2. Method 2 Use this method if your layers are […]
Read more "How to filter a layer by geometry in QGIS using Python"Creating a layer using Python is quite simple. In the following steps, we’ll create a vector layer in memory and display it on the map. First of all, enable the Python Console from the Plugins Menu (it is available in the QGIS main window). A point is created as follows: The result is: We have just […]
Read more "How to create a layer in QGIS using Python"
"How To" in QGIS 