Now, it's time to discover how to get all the features or a subset of them. The main way to iterate over all features or records of myVector is by using the following code, which shows the ID of each feature:
for feature in myVector.getFeatures(): feature.id()
This will print a list of all the 653 record IDs as shown here:
0L 1L ...[cut]... 652L
It's not always necessary to parse all records to get a subset of them. In this case, we have to set the QgsFeatureRequest class parameters to instruct getFeatures and then retrieve only a subset of records; in some cases, we must also retrieve a subset of columns.
The following code will get a subset of features and columns:
rect = QgsRectangle( 1223070.695, 2293653.357 , 9046974.211, 4184988.662)
myVector.setSubsetString(' "AREA_MI" > 1000 ')
request = QgsFeatureRequest()
request.setSubsetOfAttributes([0, 2])
request.setFilterRect( rect )
for index, feature in enumerate( myVector.getFeatures( request ) ):
print...