Multi column transformers crash when assigned to single column

[amontanez24]

Environment Details

Please indicate the following details about the environment in which you found the bug:

• RDT version: main branch
• Python version: Any
• Operating System: Any

Error Description

Both the RandomLocationGenerator and RegionalAnonymizer crash when running on one column with the following error:

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-42-a7c40dec790d> in <cell line: 29>()
     27 })
     28 
---> 29 ht.fit(data)

4 frames
/usr/local/lib/python3.10/dist-packages/rdt/hyper_transformer.py in fit(self, data)
    707                 field = column
    708 
--> 709             data = self._fit_field_transformer(data, field, self.field_transformers[field])
    710 
    711         self._validate_all_fields_fitted()

/usr/local/lib/python3.10/dist-packages/rdt/hyper_transformer.py in _fit_field_transformer(self, data, field, transformer)
    635                 transformer.fit(data, columns_to_sdtypes)
    636             else:
--> 637                 transformer.fit(data, field)
    638 
    639             self._transformers_sequence.append(transformer)

/usr/local/lib/python3.10/dist-packages/rdt/transformers/base.py in wrapper(self, *args, **kwargs)
     53         method_name = function.__name__
     54         with set_random_states(self.random_states, method_name, self.set_random_state):
---> 55             return function(self, *args, **kwargs)
     56 
     57     return wrapper

/usr/local/lib/python3.10/dist-packages/rdt/transformers/base.py in fit(self, data, columns_to_sdtypes)
    567                 Dictionary mapping each column to its sdtype.
    568         """
--> 569         self._validate_columns_to_sdtypes(data, columns_to_sdtypes)
    570         self.columns_to_sdtypes = columns_to_sdtypes
    571         self._store_columns(list(self.columns_to_sdtypes.keys()), data)

/usr/local/lib/python3.10/dist-packages/rdt/transformers/base.py in _validate_columns_to_sdtypes(self, data, columns_to_sdtypes)
    543     def _validate_columns_to_sdtypes(self, data, columns_to_sdtypes):
    544         """Check that all the columns in ``columns_to_sdtypes`` are present in the data."""
--> 545         missing = set(columns_to_sdtypes.keys()) - set(data.columns)
    546         if missing:
    547             missing_to_print = ', '.join(missing)

AttributeError: 'str' object has no attribute 'keys'

Steps to reproduce

To reproduce you can just assign one of these transformers to one column from this dataset:

from rdt.transformers import RandomLocationGenerator, RegionalAnonymizer

ht = HyperTransformer()
ht.detect_initial_config(data)

ht.update_sdtypes(column_name_to_sdtype={
    'country of departure': 'country_code',
    'region of departure': 'administrative_unit',
    'region code of departure': 'state_abbr',
    'city of departure': 'city',
    'postal code of departure': 'postcode',
    'street address of departure': 'street_address',
    'secondary address of departure': 'secondary_address',
    'country of arrival': 'country_code',
    'region of arrival': 'administrative_unit',
    'region code of arrival': 'state_abbr',
    'city of arrival': 'city',
    'postal code of arrival': 'postcode',
    'street address of arrival': 'street_address',
    'secondary address of arrival': 'secondary_address'
})

# only assign a single column (country of departure) to the RandomLocationGenerator
ht.update_transformers(column_name_to_transformer={
    ('country of departure'): RandomLocationGenerator(locales=['en_US', 'es_ES', 'en_GB'], missing_value_generation='random')

})

ht.fit(data)