Struct polars_lazy::dsl::FieldsMapper

pub struct FieldsMapper<'a> { /* private fields */ }

Implementations

impl<'a> FieldsMapper<'a>

pub fn new(fields: &'a [Field]) -> FieldsMapper<'a>

pub fn args(&self) -> &[Field]

pub fn with_same_dtype(&self) -> Result<Field, PolarsError>

Field with the same dtype.

pub fn with_dtype(&self, dtype: DataType) -> Result<Field, PolarsError>

Set a dtype.

pub fn map_dtype( &self, func: impl FnOnce(&DataType) -> DataType ) -> Result<Field, PolarsError>

Map a single dtype.

pub fn get_fields_lens(&self) -> usize

pub fn try_map_field( &self, func: impl FnOnce(&Field) -> Result<Field, PolarsError> ) -> Result<Field, PolarsError>

Map a single field with a potentially failing mapper function.

pub fn map_to_float_dtype(&self) -> Result<Field, PolarsError>

Map to a float supertype.

pub fn map_numeric_to_float_dtype(&self) -> Result<Field, PolarsError>

Map to a float supertype if numeric, else preserve

pub fn to_physical_type(&self) -> Result<Field, PolarsError>

Map to a physical type.

pub fn try_map_dtype( &self, func: impl FnOnce(&DataType) -> Result<DataType, PolarsError> ) -> Result<Field, PolarsError>

Map a single dtype with a potentially failing mapper function.

pub fn try_map_dtypes( &self, func: impl FnOnce(&[&DataType]) -> Result<DataType, PolarsError> ) -> Result<Field, PolarsError>

Map all dtypes with a potentially failing mapper function.

pub fn map_to_supertype(&self) -> Result<Field, PolarsError>

Map the dtype to the “supertype” of all fields.

pub fn map_to_list_and_array_inner_dtype(&self) -> Result<Field, PolarsError>

Map the dtype to the dtype of the list/array elements.

pub fn map_to_list_supertype(&self) -> Result<Field, PolarsError>

Map the dtypes to the “supertype” of a list of lists.

pub fn map_datetime_dtype_timezone( &self, tz: Option<&String> ) -> Result<Field, PolarsError>

Available on crate feature timezones only.

Set the timezone of a datetime dtype.

pub fn nested_sum_type(&self) -> Result<Field, PolarsError>

pub fn with_opt_dtype( &self, dtype: Option<DataType> ) -> Result<Field, PolarsError>

Available on crate feature extract_jsonpath only.

pub fn replace_dtype( &self, return_dtype: Option<DataType> ) -> Result<Field, PolarsError>

Available on crate feature replace only.