snorkel.labeling.LabelingFunction

class snorkel.labeling.LabelingFunction(name, f, resources=None, pre=None)

Bases: object

Base class for labeling functions.

A labeling function (LF) is a function that takes a data point as input and produces an integer label, corresponding to a class. A labeling function can also abstain from voting by outputting -1. For examples, see the Snorkel tutorials.

This class wraps a Python function outputting a label. Extra functionality, such as running preprocessors and storing resources, is provided. Simple LFs can be defined via a decorator. See labeling_function.

Parameters

• name (str) – Name of the LF

• f (Callable[…, int]) – Function that implements the core LF logic

• resources (Optional[Mapping[str, Any]]) – Labeling resources passed in to f via kwargs

• pre (Optional[List[BaseMapper]]) – Preprocessors to run on data points before LF execution

Raises

ValueError – Calling incorrectly defined preprocessors

name

See above

__init__(name, f, resources=None, pre=None)

Initialize self. See help(type(self)) for accurate signature.

Return type

None

Methods

__init__(name, f[, resources, pre])

Initialize self.

__call__(x)

Label data point.

Runs all preprocessors, then passes preprocessed data point to LF.

Parameters

x (Any) – Data point to label

Returns

Label for data point

Return type

int