Getting number of features in the Attribute table using PyQGIS

Question

I have a layer and I would like to access the number of rows the attribute table has from my code. Is there a way to do that without doing it like this:

num_of_features = 0

for feat in layer.getFeatures():
    num_of_features += 1

print(num_of_features)

Answer 1

Yes, there is a direct way to access the number of rows of your attribute table. Just call featureCount() method from your layer object:

num_of_features = layer.featureCount()

Answer 2

layer.getFeatures() is a Python Iterator (type: QgsFeatureIterator) so

num_of_features = len(list(layer.getFeatures()))

or you can use list comprehension:

num_of_features = len([feature for feature in layer.getFeatures()])

Answer 3

Another option can be the allFeatureIds() method from the QgsFeatureSource class:

num_of_features = len(layer.allFeatureIds())