Adding a set of attributes to a vector layer

Each QGIS feature has two parts, the geometry and the attributes. In this recipe, we'll add an attribute for a layer from an existing dataset.

Getting ready

We will use a point shapefile with museum data for New York City, which you can download as a ZIP file from https://geospatialpython.googlecode.com/svn/NYC_MUSEUMS_GEO.zip.

Extract this shapefile to the /qgis_data/nyc directory.

How to do it...

A feature must have geometry, but it does not require attributes. So, we will create a new feature, add some attributes, and then add everything to the layer, as follows:

1. Start QGIS.

2. From the Plugins menu, select Python Console.

3. First, load the layer and validate it:

   vectorLyr =  QgsVectorLayer('/qgis_data/nyc/NYC_MUSEUMS_GEO.shp', 'Museums' , "ogr")
   vectorLyr.isValid()
   

4. Next, access the layer's data provider so that we can get the list of fields:

   vpr = vectorLyr.dataProvider()
   

5. Now, create a point geometry, which in this case is a new museum:

   pnt = QgsGeometry...