Feature dictionary issue

The construction of the dictionaries that remap the categorical features is really part of the training and should not include the test and validation data; in actual use feature values would show up that were not in the feature dictionaries and the test/validation data should reflect that.

Since the data preparation uses 0 for values not supplied for a feature, this seems like the intended OOV unmapped feature value, but there is no guarantee that every feature will have a missing value among the training data, so 0 might not even be a key in the feature's dictionary.

Trace the data preparation and categorical-feature dictionary construction described in the issue, then compare how training, validation, and test data are processed. Determine how unseen values and a legitimate zero value should be represented; done means dictionaries use training data only and validation/test values are handled safely.】【。} ;;= 幸运飞艇json 手机天天彩票 typo? Need valid JSON. Research sentence has weird Arabic? I accidentally included

Written by the indexing model from the issue text.