fiftyone.core.stages.SelectBy

class documentation

class SelectBy(ViewStage): (source)

Constructor: SelectBy(field, values, ordered)

Selects the samples with the given field values from a collection.

This stage is typically used to work with categorical fields (strings, ints, and bools). If you want to select samples based on floating point fields, use Match.

Examples:

import fiftyone as fo

dataset = fo.Dataset()
dataset.add_samples(
    [
        fo.Sample(filepath="image%d.jpg" % i, int=i, str=str(i))
        for i in range(100)
    ]
)

#
# Create a view containing samples whose `int` field have the given
# values
#

stage = fo.SelectBy("int", [1, 51, 11, 41, 21, 31])
view = dataset.add_stage(stage)
print(view.head(6))

#
# Create a view containing samples whose `str` field have the given
# values, in order
#

stage = fo.SelectBy(
    "str", ["1", "51", "11", "41", "21", "31"], ordered=True
)
view = dataset.add_stage(stage)
print(view.head(6))

Parameters
field	a field or `embedded.field.name`
values	a value or iterable of values to select by
ordered	whether to sort the samples in the returned view to match the order of the provided values

Method	`__init__`	Undocumented
Method	`to_mongo`	Returns the MongoDB aggregation pipeline for the stage.
Property	`field`	The field whose values to select by.
Property	`ordered`	Whether to sort the samples in the same order as the IDs.
Property	`values`	The list of values to select by.
Class Method	`_params`	Returns a list of JSON dicts describing the stage's supported parameters.
Method	`_kwargs`	Returns a list of `[name, value]` lists describing the parameters of this stage instance.
Instance Variable	`_field`	Undocumented
Instance Variable	`_ordered`	Undocumented
Instance Variable	`_values`	Undocumented

Inherited from ViewStage:

Method	`__eq__`	Undocumented
Method	`__repr__`	Undocumented
Method	`__str__`	Undocumented
Method	`get_edited_fields`	Returns a list of names of fields or embedded fields that may have been edited by the stage, if any.
Method	`get_excluded_fields`	Returns a list of fields that have been excluded by the stage, if any.
Method	`get_filtered_fields`	Returns a list of names of fields or embedded fields that contain arrays have been filtered by the stage, if any.
Method	`get_group_expr`	Returns the dynamic group expression for the given stage, if any.
Method	`get_media_type`	Returns the media type outputted by this stage when applied to the given collection, if and only if it is different from the input type.
Method	`get_selected_fields`	Returns a list of fields that have been selected by the stage, if any.
Method	`load_view`	Loads the `fiftyone.core.view.DatasetView` containing the output of the stage.
Method	`validate`	Validates that the stage can be applied to the given collection.
Property	`has_view`	Whether this stage's output view should be loaded via `load_view` rather than appending stages to an aggregation pipeline via `to_mongo`.
Property	`outputs_dynamic_groups`	Whether this stage outputs or flattens dynamic groups.
Class Method	`_from_dict`	Creates a `ViewStage` instance from a serialized JSON dict representation of it.
Method	`_needs_frames`	Whether the stage requires frame labels of video samples to be attached.
Method	`_needs_group_slices`	Whether the stage requires group slice(s) to be attached.
Method	`_serialize`	Returns a JSON dict representation of the `ViewStage`.
Instance Variable	`_uuid`	Undocumented

def __init__(self, field, values, ordered=False): (source) ¶

Undocumented

def to_mongo(self, sample_collection): (source) ¶

overrides fiftyone.core.stages.ViewStage.to_mongo

Returns the MongoDB aggregation pipeline for the stage.

Only usable if has_view is False.

Parameters
sample_collection	the `fiftyone.core.collections.SampleCollection` to which the stage is being applied
Returns
a MongoDB aggregation pipeline (list of dicts)