fiftyone.core.stages.MapValues

Maps the values in the given field to new values for each sample in a collection.

Examples:

import random

import fiftyone as fo
import fiftyone.zoo as foz
from fiftyone import ViewField as F

ANIMALS = [
    "bear", "bird", "cat", "cow", "dog", "elephant", "giraffe",
    "horse", "sheep", "zebra"
]

dataset = foz.load_zoo_dataset("quickstart")

values = [random.choice(ANIMALS) for _ in range(len(dataset))]
dataset.set_values("str_field", values)
dataset.set_values("list_field", [[v] for v in values])

dataset.set_field("ground_truth.detections.tags", [F("label")]).save()

# Map all animals to string "animal"
mapping = {a: "animal" for a in ANIMALS}

#
# Map values in top-level fields
#

stage = fo.MapValues("str_field", mapping)
view = dataset.add_stage(stage)

print(view.count_values("str_field"))
# {"animal": 200}

stage = fo.MapValues("list_field", mapping)
view = dataset.add_stage(stage)

print(view.count_values("list_field"))
# {"animal": 200}

#
# Map values in nested fields
#

stage = fo.MapValues("ground_truth.detections.label", mapping)
view = dataset.add_stage(stage)

print(view.count_values("ground_truth.detections.label"))
# {"animal": 183, ...}

stage = fo.MapValues("ground_truth.detections.tags", mapping)
view = dataset.add_stage(stage)

print(view.count_values("ground_truth.detections.tags"))
# {"animal": 183, ...}