opendp.trans module

opendp.trans.make_bounded_resize(size, bounds, constant, TA=None)

Make a Transformation that either truncates or imputes records with constant in a Vec<TA> to match a provided size.

Parameters:

• size (int) – Number of records in output data.

• bounds (Tuple[Any, Any]) – Tuple of lower and upper bounds for data in the input domain

• constant – Value to impute with.

• TA (RuntimeTypeDescriptor) – Atomic type. If not passed, TA is inferred from the lower bound.

Returns:

A vector of the same type TA, but with the provided size.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_bounded_sum(bounds, T=None)

Make a Transformation that computes the sum of bounded data. Use make_clamp to bound data.

Parameters:

• bounds (Tuple[Any, Any]) – Tuple of lower and upper bounds for data in the input domain

• T (RuntimeTypeDescriptor) – atomic type of data

Returns:

A bounded_sum step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_cast(TIA, TOA)

Make a Transformation that casts a vector of data from type TIA to type TOA. Failure to parse results in None, else Some<TOA>.

Parameters:

• TIA (RuntimeTypeDescriptor) – atomic input data type to cast from

• TOA (RuntimeTypeDescriptor) – atomic data type to cast into

Returns:

A cast step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_cast_default(TIA, TOA)

Make a Transformation that casts a vector of data from type TIA to type TOA. If cast fails, fill with default.

Parameters:

• TIA (RuntimeTypeDescriptor) – atomic input data type to cast from

• TOA (RuntimeTypeDescriptor) – atomic data type to cast into

Returns:

A cast_default step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_cast_inherent(TIA, TOA)

Make a Transformation that casts a vector of data from type TI to a type that can represent nullity TO. If cast fails, fill with TO’s null value.

Parameters:

• TIA (RuntimeTypeDescriptor) – input data type to cast from

• TOA (RuntimeTypeDescriptor) – data type to cast into

Returns:

A cast_inherent step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_cast_metric(MI, MO, TA)

Make a Transformation that converts the dataset metric from type MI to type MO.

Parameters:

• MI (DatasetMetric) – input dataset metric

• MO (DatasetMetric) – output dataset metric

• TA (RuntimeTypeDescriptor) – atomic type of data

Returns:

A cast_metric step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_clamp(bounds, TA=None)

Make a Transformation that clamps numeric data in Vec<T> to bounds. If datum is less than lower, let datum be lower. If datum is greater than upper, let datum be upper.

Parameters:

• bounds (Tuple[Any, Any]) – Tuple of inclusive lower and upper bounds.

• TA (RuntimeTypeDescriptor) – atomic data type

Returns:

A clamp step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_count(TIA, TO='i32')

Make a Transformation that computes a count of the number of records in data.

Parameters:

• TIA (RuntimeTypeDescriptor) – Atomic Input Type. Input data is expected to be of the form Vec<TIA>.

• TO (RuntimeTypeDescriptor) – Output Type. Must be an integer.

Returns:

A count step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_count_by(size, MO, TIA, TOA='i32')

Make a Transformation that computes the count of each unique value in data. This assumes that the category set is unknown. This uses a restricted-sensitivity proof that takes advantage of known dataset size. Use make_resize to establish dataset size. Use meas.make_base_stability to release this query.

Parameters:

• size (int) – Number of records in input data.

• MO (SensitivityMetric) – Output Metric.

• TIA (RuntimeTypeDescriptor) – Atomic Input Type. Categorical/hashable input data type. Input data must be Vec<TI>.

• TOA (RuntimeTypeDescriptor) – Atomic Output Type. Express counts in terms of this integral type.

Returns:

The carrier type is HashMap<TI, TO>- the counts for each unique data input.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_count_by_categories(categories, MO='L1Distance<i32>', TIA=None, TOA='i32')

Make a Transformation that computes the number of times each category appears in the data. This assumes that the category set is known.

Parameters:

• categories (Any) – The set of categories to compute counts for.

• MO (SensitivityMetric) – output sensitivity metric

• TIA (RuntimeTypeDescriptor) – categorical/hashable input type. Input data must be Vec<TIA>.

• TOA (RuntimeTypeDescriptor) – express counts in terms of this integral type

Returns:

A count_by_categories step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_count_distinct(TIA, TO='i32')

Make a Transformation that computes a count of the number of unique, distinct records in data.

Parameters:

• TIA (RuntimeTypeDescriptor) – Atomic Input Type. Input data is expected to be of the form Vec<TIA>.

• TO (RuntimeTypeDescriptor) – Output Type. Must be an integer.

Returns:

A count_distinct step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_create_dataframe(col_names, K=None)

Make a Transformation that constructs a dataframe from a Vec<Vec<String>>.

Parameters:

• col_names (Any) – Column names for each record entry.

• K (RuntimeTypeDescriptor) – categorical/hashable data type of column names

Returns:

A create_dataframe step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_identity(D, M)

Make a Transformation that simply passes the data through.

Parameters:

• D (RuntimeTypeDescriptor) – Domain of the identity function. Must be VectorDomain<AllDomain<_>> or AllDomain<_>

• M (RuntimeTypeDescriptor) – metric. Must be a dataset metric if D is a VectorDomain or a sensitivity metric if D is an AllDomain

Returns:

A transformation where the input and output domain are D and the input and output metric are M

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_impute_constant(constant, DA='OptionNullDomain<AllDomain<TA>>')

Make a Transformation that replaces null/None data with constant. By default, the input type is Vec<Option<TA>>, as emitted by make_cast. Set DA to InherentNullDomain<AllDomain<TA>> for imputing on types that have an inherent representation of nullity, like floats.

Parameters:

• constant (Any) – Value to replace nulls with.

• DA (RuntimeTypeDescriptor) – domain of data being imputed. This is OptionNullDomain<AllDomain<TA>> or InherentNullDomain<AllDomain<TA>>

Returns:

A impute_constant step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_impute_uniform_float(bounds, TA=None)

Make a Transformation that replaces null/None data in Vec<TA> with uniformly distributed floats within bounds.

Parameters:

• bounds (Tuple[Any, Any]) – Tuple of inclusive lower and upper bounds.

• TA (RuntimeTypeDescriptor) – type of data being imputed

Returns:

A impute_uniform_float step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_is_equal(value, TIA=None)

Make a Transformation that checks if each element is equal to value.

Parameters:

• value (Any) – value to check against

• TIA (RuntimeTypeDescriptor) – atomic input data type

Returns:

A is_equal step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_is_null(DIA)

Make a Transformation that checks if each element in a vector is null.

Parameters:

DIA (RuntimeTypeDescriptor) – atomic input domain

Returns:

A is_null step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_resize(size, constant, TA=None)

Make a Transformation that either truncates or imputes records with constant in a Vec<TA> to match a provided size.

Parameters:

• size (int) – Number of records in output data.

• constant (Any) – Value to impute with.

• TA (RuntimeTypeDescriptor) – Atomic type.

Returns:

A vector of the same type TA, but with the provided size.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_select_column(key, TOA, K=None)

Make a Transformation that retrieves the column key from a dataframe as Vec<TOA>.

Parameters:

• key (Any) – categorical/hashable data type of the key/column name

• K (RuntimeTypeDescriptor) – data type of the key

• TOA (RuntimeTypeDescriptor) – atomic data type to downcast to

Returns:

A select_column step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_sized_bounded_mean(size, bounds, T=None)

Make a Transformation that computes the mean of bounded data. This uses a restricted-sensitivity proof that takes advantage of known dataset size. Use make_clamp to bound data and make_bounded_resize to establish dataset size.

Parameters:

• size (int) – Number of records in input data.

• bounds (Tuple[Any, Any]) – Tuple of inclusive lower and upper bounds of the input data.

• T (RuntimeTypeDescriptor) – atomic data type

Returns:

A sized_bounded_mean step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_sized_bounded_sum(size, bounds, T=None)

Make a Transformation that computes the sum of bounded data with known dataset size. This uses a restricted-sensitivity proof that takes advantage of known dataset size for better utility. Use make_clamp to bound data and make_bounded_resize to establish dataset size.

Parameters:

• size (int) – Number of records in input data.

• bounds (Tuple[Any, Any]) – Tuple of lower and upper bounds for input data

• T (RuntimeTypeDescriptor) – atomic type of data

Returns:

A sized_bounded_sum step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_sized_bounded_variance(size, bounds, ddof=1, T=None)

Make a Transformation that computes the variance of bounded data. This uses a restricted-sensitivity proof that takes advantage of known dataset size. Use make_clamp to bound data and make_bounded_resize to establish dataset size.

Parameters:

• size (int) – Number of records in input data.

• bounds (Tuple[Any, Any]) – Tuple of lower and upper bounds for input data

• ddof (int) – Delta degrees of freedom. Set to 0 if not a sample, 1 for sample estimate.

• T (RuntimeTypeDescriptor) – atomic data type

Returns:

A sized_bounded_variance step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_split_dataframe(separator, col_names, K=None)

Make a Transformation that splits each record in a String into a Vec<Vec<String>>, and loads the resulting table into a dataframe keyed by col_names.

Parameters:

• separator (str) – The token(s) that separate entries in each record.

• col_names (Any) – Column names for each record entry.

• K (RuntimeTypeDescriptor) – categorical/hashable data type of column names

Returns:

A split_dataframe step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_split_lines()

Make a Transformation that takes a string and splits it into a Vec<String> of its lines.

Returns:

A split_lines step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_split_records(separator)

Make a Transformation that splits each record in a Vec<String> into a Vec<Vec<String>>.

Parameters:

separator (str) – The token(s) that separate entries in each record.

Returns:

A split_records step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library

opendp.trans.make_unclamp(bounds, TA=None)

Make a Transformation that unclamps a VectorDomain<BoundedDomain<T>> to a VectorDomain<AllDomain<T>>.

Parameters:

• bounds (Tuple[Any, Any]) – Tuple of inclusive lower and upper bounds.

• TA (RuntimeTypeDescriptor) – atomic data type

Returns:

A unclamp step.

Return type:

Transformation

Raises:

• AssertionError – if an argument’s type differs from the expected type

• UnknownTypeError – if a type-argument fails to parse

• OpenDPException – packaged error from the core OpenDP library