Simplifying user defined features

    features_data = []

    ############################################################## DEBUG

    df[featurizer.feature_fields] = df[featurizer.feature_fields].apply(pd.to_numeric)

    ############################################################## DEBUG

    for ind, row in df.iterrows():

      # pandas rows are tuples (row_num, row_data)

      feature_list = []

      for feature_name in featurizer.feature_fields:

        feature_list.append(row[feature_name])

      features_data.append(np.array(feature_list))

    df[featurizer.__class__.__name__] = features_data

    X_shard = df.as_matrix(columns=featurizer.feature_fields)

    df[featurizer.__class__.__name__] = X_shard.tolist()

    ############################################################## DEBUG

    #for ind, row in df.iterrows():

    #  # pandas rows are tuples (row_num, row_data)

    #  feature_list = []

    #  for feature_name in featurizer.feature_fields:

    #    feature_list.append(row[feature_name])

    #  features_data.append(np.array(feature_list))

    #df[featurizer.__class__.__name__] = features_data

    ############################################################## DEBUG

    time2 = time.time()

    print("USER SPECIFIED PROCESSING TOOK %0.3f s" % (time2-time1))