hover.utils.snorkel_helper

• labeling_function(targets, label_encoder=None, **kwargs)

  Hover's flavor of the Snorkel labeling_function decorator.

  However, due to the dynamic label encoding nature of hover, the decorated function should return the original string label, not its encoding integer.

  • assigns a UUID for easy identification
  • keeps track of LF targets

  Param	Type	Description
  targets	list of str	labels that the labeling function is intended to create
  label_encoder	dict	{decoded_label -> encoded_label} mapping, if you also want an original snorkel-style labeling function linked as a .snorkel attribute
  **kwargs		forwarded to snorkel's labeling_function()

  Source code in hover/utils/snorkel_helper.py

  def labeling_function(targets, label_encoder=None, **kwargs):
      """
      ???+ note "Hover's flavor of the Snorkel labeling_function decorator."
          However, due to the dynamic label encoding nature of hover,
          the decorated function should return the original string label, not its encoding integer.
  
          - assigns a UUID for easy identification
          - keeps track of LF targets
  
          | Param           | Type   | Description                          |
          | :-------------- | :----- | :----------------------------------- |
          | `targets`       | `list` of `str` | labels that the labeling function is intended to create |
          | `label_encoder` | `dict` | {decoded_label -> encoded_label} mapping, if you also want an original snorkel-style labeling function linked as a `.snorkel` attribute |
          | `**kwargs`      |        | forwarded to `snorkel`'s `labeling_function()` |
      """
      # lazy import so that the package does not require snorkel
      # Feb 3, 2022: snorkel's dependency handling is too strict
      # for other dependencies like NumPy, SciPy, SpaCy, etc.
      # Let's cite Snorkel and lazy import or copy functions.
      # DO NOT explicitly depend on Snorkel without confirming
      # that all builds/tests pass by Anaconda standards, else
      # we risk having to drop conda support.
      from snorkel.labeling import (
          labeling_function as snorkel_lf,
          LabelingFunction as SnorkelLF,
      )
  
      def wrapper(func):
          # set up kwargs for Snorkel's LF
          # a default name that can be overridden
          snorkel_kwargs = {"name": func.__name__}
          snorkel_kwargs.update(kwargs)
  
          # return value of hover's decorator
          lf = SnorkelLF(f=func, **snorkel_kwargs)
  
          # additional attributes
          lf.uuid = uuid.uuid1()
          lf.targets = targets[:]
  
          # link a snorkel-style labeling function if applicable
          if label_encoder:
              lf.label_encoder = label_encoder
  
              def snorkel_style_func(x):
                  return lf.label_encoder[func(x)]
  
              lf.snorkel = snorkel_lf(**kwargs)(snorkel_style_func)
          else:
              lf.label_encoder = None
              lf.snorkel = None
  
          return lf
  
      return wrapper