`format_as_html(explain(prediction(...))` fails to show the highlighted text

[tsela]

Hi,

I'm trying to use eli5 to explain the results of a simple Scikit-Learn pipeline made of a TfIdfVectorizer and a LogisticRegressionCV. In particular, I'm trying to replicate the looks of the results of eli5.show_prediction() as shown in https://eli5.readthedocs.io/en/latest/tutorials/sklearn-text.html, but using format_as_html() and explain_prediction() directly, since I'm building a web app rather than working with Jupyter.

The problem I have is that whatever I'm trying, I only get a weight table as output, and the highlighted text is missing. Even when I set force_weights to False, it still only shows the weight table. I've inspected the output of format_as_html() and I can't find any trace of highlighted text, only the HTML for the table. So it's not a case of styling moving the highlighted text away, it's quite simply missing.

Even checking the source code doesn't help, and I feel like I'm missing something. Is there a reason why I can't get the highlighted text to show up?

[lopuhin]

@tsela I see, that sounds very reasonable. Does eli5.show_prediction() show the text explanations on your pipeline?

[tsela]

@lopuhin I just checked, and no, eli5.show_prediction() only shows the weight table as well. Any idea where that comes from? My pipeline is relative simple, with the only complication is that I load the model from a pickled file using joblib, and I use a custom tokeniser in the TfIdfVectoriser. Could one of these be the issue?

[lopuhin]

The issue is likely due to a custom tokenizer, here is the relevant code which checks the class I believe:

eli5/eli5/sklearn/text.py

Lines 53 to 70 in 017c738

	def _get_doc_weighted_spans(doc,
	vec,
	feature_weights, # type: FeatureWeights
	feature_fn=None # type: Optional[Callable[[str], str]]
	):
	# type: (...) -> Optional[Tuple[FoundFeatures, DocWeightedSpans]]
	if isinstance(vec, InvertableHashingVectorizer):
	vec = vec.vec
	if hasattr(vec, 'get_doc_weighted_spans'):
	return vec.get_doc_weighted_spans(doc, feature_weights, feature_fn)
	if not isinstance(vec, VectorizerMixin):
	return None
	span_analyzer, preprocessed_doc = build_span_analyzer(doc, vec)
	if span_analyzer is None:
	return None

and also

eli5/eli5/sklearn/_span_analyzers.py

Line 7 in 017c738

def build_span_analyzer(document, vec):

so one option it so define a get_doc_weighted_spans method on your vectorizer - sorry this part is not really documented, you'll have to check the source.

[tsela]

Thanks for your help! It looks indeed like the custom tokeniser is the problem. I'm kind of misusing the tokeniser to do all the text preprocessing (so that the pickled model is the only thing I have to send around for whoever will be working on the production frontend), so it's quite understandable that this could cause the problem.

I'll see if I can define a get_doc_weighted_spans() method. My tokeniser is lossy (on purpose), so that might be a challenge, but I'll try and see if it's possible.

Thanks for your help!

[hohl]

I'm having the same issue. Tried both eli5.show_prediction() and eli5.explain_weights together with eli5.format_as_html. Both show me the table, but no nicely formatted text with coloured overlays.

But I am not using a custom tokenizer. Instead, I even tried to use just a plain TfIdfVectorizer() with all parameters left to their default values and it still didn't work.

I then even tried whether it works with TextExplainer:

te = TextExplainer()
te.fit(samples[0], model.predict_proba)
te.show_prediction()

But then again only showed the table and no highlighted text. Any other ideas what I could try?

Eli5 version is 0.10.1. scikit-learn is 0.22.1. Tried to run on two different machines too: one running Ubuntu and one running macOS.

[hohl]

I now even tried to run one of the sample notebooks in this repo. I hoped that I am just using the library wrong, but that does not seem to be the case.

The output of the first block with explain_prediction (..., force_weights=False, ...) does also not show me the highlighted text, but just the weights table, even thought force_weights is set to False in that sample.

I also tried whether it changes anything when I downgrade ELI5 to 0.10 or 0.9.0, but both these versions delivered the same results as the 0.10.1 release.

[hohl]

Finally found some configuration that worked: Downgrading scikit-learn to 0.21.3 does finally output the texts. I guess there is some incompatibility of sckit-learn 0.22 and ELI5 0.10.1?

[sobayed]

Same issue here, the highlighted text does not show for show_prediction() with ELI5 0.10.1 and scikit-learn 0.22

[Querela]

I'm also on the latest versions, trying to get a transformer-based explanation, but just using a prediction method and not getting any highlighted text. According to this: https://eli5.readthedocs.io/en/latest/tutorials/black-box-text-classifiers.html

def predict_proba(docs):
    # here obviously with code ...
   pass

label_list = ["0", "1"]
doc = "My example sentence expressing a strong optionen etc."

# ---

te = TextExplainer(random_state=42)
te.fit(doc, predict_proba)
te.show_prediction(target_names=label_list)

Fishing through the source, it might be some check, like this:

eli5/eli5/sklearn/text.py

Line 65 in 4839d19

if not isinstance(vec, VectorizerMixin):

(suggested by @lopuhin )
The code above is for sklearn, but stuffing my te.doc_, te.vec_, te.explain_prediction().targets[0].feature_weights into _get_doc_weighted_spans fails on VectorizerMixin. This may be related but I can be wrong...

[lefterisloukas]

Same problem here. Could not show highlighted text, either in Jupyter, neither in other envs.
Solved it with what @hohl suggested.

[bakarep]

@lopuhin , Was this looked into by eli5 team to make sure eli5 is compatible with latest version of sklearn ?
I also tried downgrading sklearn but I am getting other issues like:
ModuleNotFoundError: No module named 'sklearn.feature_selection._univariate_selection'

Request to please help with permanent solution

[datanizing]

VectorizerMixin was renamed to _VectorizerMixin in scikit-learn 0.22. Changing that in the code text.py (two occurences) as @Querela mentioned makes it work again.

[jonas-nothnagel]

Hi everyone, is there a fix now? I downgraded scikit-learn to 0.21.3 and still are not able to see any highlighted text unfortunately.

[Bougeant]

Hi @jonas-nothnagel, it looks like @icfly2 has submitted a PR for this fix. I'm not sure what needs to happen for his work to be merged in.