Fix empty dataframe handling in conditional sampling

[omelyanchikd]

Resolves #2334

Error 1:

• If single table synthesizer model doesn't produce any valid samples while trying to sample remaining columns, method _filter_conditions will throw an unhandled error when trying to access any of dataframe columns, because it is empty, and sampling will be stopped:

From sdv/single_table/base.py/_sample_rows

            sampled = self._data_processor.filter_valid(sampled)

            if conditions is not None:
                sampled = self._filter_conditions(sampled, conditions, float_rtol)

Line causing an error from sdv/single_table/base.py/_filter_conditions

        for column, value in conditions.items():
            column_values = sampled[column]

Error 2:

• If single table synthesizer model has more than one constraint, and one of these constraints filters out all rows in the generated sample while trying to sample remaining columns, loop in method filter_valid will throw an unhandled error when trying to access any of sample dataframe columns, because it is empty, and sampling will be stopped:

From sdv/data_processing/data_processor.py/filter_valid

        for constraint in self._constraints:
            data = constraint.filter_valid(data)

[sdv-team]

Hi @omelyanchikd , it’s great to see your interest in the SDV ecosystem. The SDV software (and its related libraries) is owned and maintained by DataCebo. It is available under the Business Source License for you to browse.

We are a small team supporting a large set of users with enterprise-specific intricacies and reliability needs. This has required us to be deliberate about setting the roadmap for SDV libraries. As a result, we are unable to prioritize reviewing and accepting external pull requests.

Is your PR is meant to address a bug or feature request? If you haven't already, we would greatly appreciate it if you could file an issue instead with the overall description of your problem. We can determine whether it’s aligned with our framework. Once discussed, our team typically resolves smaller issues within a few release cycles. We appreciate your understanding.

[omelyanchikd]

Hi @omelyanchikd , it’s great to see your interest in the SDV ecosystem. The SDV software (and its related libraries) is owned and maintained by DataCebo. It is available under the Business Source License for you to browse.

We are a small team supporting a large set of users with enterprise-specific intricacies and reliability needs. This has required us to be deliberate about setting the roadmap for SDV libraries. As a result, we are unable to prioritize reviewing and accepting external pull requests.

Is your PR is meant to address a bug or feature request? If you haven't already, we would greatly appreciate it if you could file an issue instead with the overall description of your problem. We can determine whether it’s aligned with our framework. Once discussed, our team typically resolves smaller issues within a few release cycles. We appreciate your understanding.

Yes, I am already reporting a bug in #2334 .