Error when fitting exported ensemble

[robertmartin8]

After exporting my ensemble and trying to fit the new base_learner to my data, I encountered the following error:

FutureWarning: 
Passing list-likes to .loc or [] with any missing label will raise
KeyError in the future, you can use .reindex() as an alternative.
See the documentation here:
http://pandas.pydata.org/pandas-docs/stable/indexing.html#deprecate-loc-reindex-listlike
  return self.loc[key]

I don't fully understand the error, but after a bit of digging I found that the guilty line was

base_learner.fit(X[train_idx], y[train_idx]), under the fit method of the XcessivStackedEnsemble class. I fixed this by using y.iloc[train_idx] instead of y[train_idx].

I don't know if this is just a case of human error, but for anyone else having the same issue, this fixed it for me.

[GillesVandewiele]

It's a pandas warning. loc or iloc should be use, depending on the context and the values in train_idx (if they are values from the index column of the dataframe or just "literal indexes" (as in the position in the dataframe)).

[GillesVandewiele]

I reproduced this warning. You can fix it by passing numpy matrices instead of Pandas DataFrames to the base learner.

X.values instead of X does the trick ;)