fiftyone.core.aggregations.Count

Counts the number of field values in a collection.

None-valued fields are ignored.

If no field or expression is provided, the samples themselves are counted.

Examples:

import fiftyone as fo
from fiftyone import ViewField as F

dataset = fo.Dataset()
dataset.add_samples(
    [
        fo.Sample(
            filepath="/path/to/image1.png",
            predictions=fo.Detections(
                detections=[
                    fo.Detection(label="cat"),
                    fo.Detection(label="dog"),
                ]
            ),
        ),
        fo.Sample(
            filepath="/path/to/image2.png",
            predictions=fo.Detections(
                detections=[
                    fo.Detection(label="cat"),
                    fo.Detection(label="rabbit"),
                    fo.Detection(label="squirrel"),
                ]
            ),
        ),
        fo.Sample(
            filepath="/path/to/image3.png",
            predictions=None,
        ),
    ]
)

#
# Count the number of samples in the dataset
#

aggregation = fo.Count()
count = dataset.aggregate(aggregation)
print(count)  # the count

#
# Count the number of samples with `predictions`
#

aggregation = fo.Count("predictions")
count = dataset.aggregate(aggregation)
print(count)  # the count

#
# Count the number of objects in the `predictions` field
#

aggregation = fo.Count("predictions.detections")
count = dataset.aggregate(aggregation)
print(count)  # the count

#
# Count the number of objects in samples with > 2 predictions
#

aggregation = fo.Count(
    (F("predictions.detections").length() > 2).if_else(
        F("predictions.detections"), None
    )
)
count = dataset.aggregate(aggregation)
print(count)  # the count