transform#
- pylibcudf.transform.bools_to_mask(Column input) tuple#
Create a bitmask from a column of boolean elements
- Parameters:
- inputColumn
Column to produce new mask from.
- Returns:
- tuple[gpumemoryview, int]
Two-tuple of a gpumemoryview wrapping the bitmask and the null count.
- pylibcudf.transform.compute_column(Table input, Expression expr) Column#
Create a column by evaluating an expression on a table.
For details see
compute_column().- Parameters:
- inputTable
Table used for expression evaluation
- exprExpression
Expression to evaluate
- Returns:
- Column of the evaluated expression
- pylibcudf.transform.encode(Table input) tuple#
Encode the rows of the given table as integers.
- Parameters:
- inputTable
Table containing values to be encoded
- Returns:
- tuple[Table, Column]
The distinct row of the input table in sorted order, and a column of integer indices representing the encoded rows.
- pylibcudf.transform.mask_to_bools(Py_ssize_t bitmask, int begin_bit, int end_bit) Column#
Creates a boolean column from given bitmask.
- Parameters:
- bitmaskint
Pointer to the bitmask which needs to be converted
- begin_bitint
Position of the bit from which the conversion should start
- end_bitint
Position of the bit before which the conversion should stop
- Returns:
- Column
Boolean column of the bitmask from [begin_bit, end_bit]
- pylibcudf.transform.nans_to_nulls(Column input) tuple#
Create a null mask preserving existing nulls and converting nans to null.
For details, see
nans_to_nulls().- Parameters:
- inputColumn
Column to produce new mask from.
- Returns:
- Two-tuple of a gpumemoryview wrapping the null mask and the new null count.
- pylibcudf.transform.one_hot_encode(Column input, Column categories) Table#
Encodes input by generating a new column for each value in categories indicating the presence of that value in input.
- Parameters:
- inputColumn
Column containing values to be encoded.
- categoriesColumn
Column containing categories
- Returns:
- Column
A table of the encoded values.
- pylibcudf.transform.transform(Column input, unicode unary_udf, DataType output_type, bool is_ptx) Column#
- Create a new column by applying a unary function against every
element of an input column.
- Parameters:
- inputColumn
Column to transform.
- unary_udfstr
The PTX/CUDA string of the unary function to apply.
- output_typeDataType
The output type that is compatible with the output type in the unary_udf.
- is_ptxbool
If True, the UDF is treated as PTX code. If False, the UDF is treated as CUDA code.
- Returns:
- Column
The transformed column having the UDF applied to each element.