TabularDataModule: Fix pandas returning a series when calling nunique() (#420)

* Fix pandas returning a series when calling nunique()

Fixes #404 (comment)

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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Manu Joseph V <manujosephv@gmail.com>

Author: 3 people

src/pytorch_tabular/tabular_datamodule.py

@@ -290,11 +290,11 @@ def _update_config(self, config) -> InferredConfig:
             raise ValueError(f"{config.task} is an unsupported task.")
         if self.train is not None:
             categorical_cardinality = [
-                int(self.train[col].fillna("NA").nunique()) + 1 for col in config.categorical_cols
+                int(x) + 1 for x in list(self.train[config.categorical_cols].fillna("NA").nunique().values)
             ]
         else:
             categorical_cardinality = [
-                int(self.train_dataset.data[col].nunique()) + 1 for col in config.categorical_cols
+                int(x) + 1 for x in list(self.train_dataset.data[config.categorical_cols].nunique().values)
             ]
         if getattr(config, "embedding_dims", None) is not None:
             embedding_dims = config.embedding_dims