When decorated, labeling functions do not work with Fonduer

[HiromuHota]

Describe the bug

Say I have a set of labeling functions like below:

def check(x):
    return SPAM if "check" in x.text.lower() else ABSTAIN

I wanted to use snorkel.labeling.LFAnalysis as described in https://www.snorkel.org/use-cases/01-spam-tutorial#c-evaluate-performance-on-training-set. To do this, I had to decorate labeling functions as below:

from snorkel.labeling import labeling_function

@labeling_function()
def check(x):
    return SPAM if "check" in x.text.lower() else ABSTAIN

When labeling functions get decorated as snorkel.labeling.LabelingFunction, fonduer.supervision.Labeler.apply stops working.

To Reproduce Steps to reproduce the behavior:

1. Decorate labeling functions as snorkel.labeling.LabelingFunction
2. Run Labeler.apply

Expected behavior

Decorated labeling functions work with fonduer.supervision.Labeler.apply.

Error Logs/Screenshots

Process LabelerUDF-54:
Process LabelerUDF-55:
Traceback (most recent call last):
Traceback (most recent call last):
  File "/usr/local/Cellar/python/3.7.7/Frameworks/Python.framework/Versions/3.7/lib/python3.7/multiprocessing/process.py", line 297, in _bootstrap
    self.run()
  File "/usr/local/Cellar/python/3.7.7/Frameworks/Python.framework/Versions/3.7/lib/python3.7/multiprocessing/process.py", line 297, in _bootstrap
    self.run()
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/utils/udf.py", line 207, in run
    y = self.apply(doc, **self.apply_kwargs)
Process LabelerUDF-53:
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/utils/udf.py", line 207, in run
    y = self.apply(doc, **self.apply_kwargs)
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 481, in apply
    list(get_mapping(table, cands, self._f_gen)) for cands in cands_list
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 481, in apply
    list(get_mapping(table, cands, self._f_gen)) for cands in cands_list
Traceback (most recent call last):
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 481, in <listcomp>
    list(get_mapping(table, cands, self._f_gen)) for cands in cands_list
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 481, in <listcomp>
    list(get_mapping(table, cands, self._f_gen)) for cands in cands_list
  File "/usr/local/Cellar/python/3.7.7/Frameworks/Python.framework/Versions/3.7/lib/python3.7/multiprocessing/process.py", line 297, in _bootstrap
    self.run()
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/utils/utils_udf.py", line 219, in get_mapping
    for cid, key, value in generator(cand):
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/utils/utils_udf.py", line 219, in get_mapping
    for cid, key, value in generator(cand):
Process LabelerUDF-52:
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/utils/udf.py", line 207, in run
    y = self.apply(doc, **self.apply_kwargs)
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 438, in _f_gen
    for cid, lf_key, label in labels(c):
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 438, in _f_gen
    for cid, lf_key, label in labels(c):
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 437, in <lambda>
    labels = lambda c: [(c.id, lf.__name__, lf(c)) for lf in self.lfs[lf_idx]]
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 437, in <lambda>
    labels = lambda c: [(c.id, lf.__name__, lf(c)) for lf in self.lfs[lf_idx]]
Traceback (most recent call last):
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 481, in apply
    list(get_mapping(table, cands, self._f_gen)) for cands in cands_list
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 437, in <listcomp>
    labels = lambda c: [(c.id, lf.__name__, lf(c)) for lf in self.lfs[lf_idx]]
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 437, in <listcomp>
    labels = lambda c: [(c.id, lf.__name__, lf(c)) for lf in self.lfs[lf_idx]]
  File "/usr/local/Cellar/python/3.7.7/Frameworks/Python.framework/Versions/3.7/lib/python3.7/multiprocessing/process.py", line 297, in _bootstrap
    self.run()
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 481, in <listcomp>
    list(get_mapping(table, cands, self._f_gen)) for cands in cands_list
AttributeError: 'LabelingFunction' object has no attribute '__name__'
AttributeError: 'LabelingFunction' object has no attribute '__name__'
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/utils/utils_udf.py", line 219, in get_mapping
    for cid, key, value in generator(cand):
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/utils/udf.py", line 207, in run
    y = self.apply(doc, **self.apply_kwargs)
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 481, in apply
    list(get_mapping(table, cands, self._f_gen)) for cands in cands_list
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 438, in _f_gen
    for cid, lf_key, label in labels(c):
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 481, in <listcomp>
    list(get_mapping(table, cands, self._f_gen)) for cands in cands_list
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 437, in <lambda>
    labels = lambda c: [(c.id, lf.__name__, lf(c)) for lf in self.lfs[lf_idx]]
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/utils/utils_udf.py", line 219, in get_mapping
    for cid, key, value in generator(cand):
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 437, in <listcomp>
    labels = lambda c: [(c.id, lf.__name__, lf(c)) for lf in self.lfs[lf_idx]]
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 438, in _f_gen
    for cid, lf_key, label in labels(c):
AttributeError: 'LabelingFunction' object has no attribute '__name__'
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 437, in <lambda>
    labels = lambda c: [(c.id, lf.__name__, lf(c)) for lf in self.lfs[lf_idx]]
  File "/Users/hiromu/workspace/fonduer-tutorials/.venv/lib/python3.7/site-packages/fonduer/supervision/labeler.py", line 437, in <listcomp>
    labels = lambda c: [(c.id, lf.__name__, lf(c)) for lf in self.lfs[lf_idx]]
AttributeError: 'LabelingFunction' object has no attribute '__name__'

Environment (please complete the following information):

• Fonduer Version: 0.8.1

Additional context I'm updating Fonduer tutorials for v0.8.1.