Struct DataTypeMap 

pub struct DataTypeMap {
    pub arrow_type: PyDataType,
    pub python_type: PythonType,
    pub sql_type: SqlType,
}

These bindings are tying together several disparate systems. You have SQL types for the SQL strings and RDBMS systems itself. Rust types for the DataFusion code Arrow types which represents the underlying arrow format Python types which represent the type in Python It is important to keep all of those types in a single and manageable location. Therefore this structure exists to map those types and provide a simple place for developers to map types from one system to another.

Fields

arrow_type: PyDataType

python_type: PythonType

sql_type: SqlType

Implementations

impl DataTypeMap

pub fn map_from_arrow_type(arrow_type: &DataType) -> Result<DataTypeMap, PyErr>

pub fn map_from_scalar_value( scalar_val: &ScalarValue, ) -> Result<DataTypeMap, PyErr>

Generate the DataTypeMap from a ScalarValue instance

pub fn map_from_scalar_to_arrow( scalar_val: &ScalarValue, ) -> Result<DataType, PyErr>

Maps a ScalarValue to an Arrow DataType

impl DataTypeMap

pub fn py_new( arrow_type: PyDataType, python_type: PythonType, sql_type: SqlType, ) -> Self

pub fn py_map_from_parquet_type_str( parquet_str_type: String, ) -> PyResult<DataTypeMap>

When using pyarrow.parquet.read_metadata().schema.column(x).physical_type you are presented with a String type for schema rather than an object type. Here we make a best effort to convert that to a physical type.

pub fn py_map_from_arrow_type(arrow_type: &PyDataType) -> PyResult<DataTypeMap>

pub fn py_map_from_arrow_type_str( arrow_type_str: String, ) -> PyResult<DataTypeMap>

pub fn py_map_from_sql_type(sql_type: &SqlType) -> PyResult<DataTypeMap>

pub fn friendly_arrow_type_name(&self) -> PyResult<&str>

Unfortunately PyO3 does not allow for us to expose the DataType as an enum since we cannot directly annotate the Enum instance of dependency code. Therefore, here we provide an enum to mimic it.

Trait Implementations

impl Clone for DataTypeMap

fn clone(&self) -> DataTypeMap

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DataTypeMap

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl DerefToPyAny for DataTypeMap

impl<'a, 'py> FromPyObject<'a, 'py> for DataTypeMap

where Self: Clone,

type Error = PyClassGuardError<'a, 'py>

The type returned in the event of a conversion error.

fn extract( obj: Borrowed<'a, 'py, PyAny>, ) -> Result<Self, <Self as FromPyObject<'a, 'py>>::Error>

Extracts Self from the bound smart pointer obj.

impl<'py> IntoPyObject<'py> for DataTypeMap

type Target = DataTypeMap

The Python output type

type Output = Bound<'py, <DataTypeMap as IntoPyObject<'py>>::Target>

The smart pointer type to use.

type Error = PyErr

The type returned in the event of a conversion error.

fn into_pyobject( self, py: Python<'py>, ) -> Result<<Self as IntoPyObject<'_>>::Output, <Self as IntoPyObject<'_>>::Error>

Performs the conversion.

impl PyClass for DataTypeMap

const NAME: &str = "DataTypeMap"

Name of the class.

type Frozen = False

Whether the pyclass is frozen.

impl PyClassBaseType for DataTypeMap

type LayoutAsBase = <DataTypeMap as PyClassImpl>::Layout

type BaseNativeType = <DataTypeMap as PyClassImpl>::BaseNativeType

type Initializer = PyClassInitializer<DataTypeMap>

type PyClassMutability = <DataTypeMap as PyClassImpl>::PyClassMutability

type Layout<T: PyClassImpl> = <<DataTypeMap as PyClassBaseType>::BaseNativeType as PyClassBaseType>::Layout<T>

The type of object layout to use for ancestors or descendants of this type.

impl PyClassImpl for DataTypeMap

const MODULE: Option<&str>

Module which the class will be associated with.

const IS_BASETYPE: bool = true

#[pyclass(subclass)]

const IS_SUBCLASS: bool = false

#[pyclass(extends=…)]

const IS_MAPPING: bool = false

#[pyclass(mapping)]

const IS_SEQUENCE: bool = false

#[pyclass(sequence)]

const IS_IMMUTABLE_TYPE: bool = false

#[pyclass(immutable_type)]

const RAW_DOC: &'static CStr = /// These bindings are tying together several disparate systems. /// You have SQL types for the SQL strings and RDBMS systems itself. /// Rust types for the DataFusion code /// Arrow types which represents the underlying arrow format /// Python types which represent the type in Python /// It is important to keep all of those types in a single /// and manageable location. Therefore this structure exists /// to map those types and provide a simple place for developers /// to map types from one system to another.

Docstring for the class provided on the struct or enum.

const DOC: &'static CStr

Fully rendered class doc, including the text_signature if a constructor is defined.

type Layout = <<DataTypeMap as PyClassImpl>::BaseNativeType as PyClassBaseType>::Layout<DataTypeMap>

Description of how this class is laid out in memory

type BaseType = PyAny

Base class

type ThreadChecker = NoopThreadChecker

This handles following two situations:

type PyClassMutability = <<PyAny as PyClassBaseType>::PyClassMutability as PyClassMutability>::MutableChild

Immutable or mutable

type Dict = PyClassDummySlot

Specify this class has #[pyclass(dict)] or not.

type WeakRef = PyClassDummySlot

Specify this class has #[pyclass(weakref)] or not.

type BaseNativeType = PyAny

The closest native ancestor. This is PyAny by default, and when you declare #[pyclass(extends=PyDict)], it’s PyDict.

fn items_iter() -> PyClassItemsIter

fn lazy_type_object() -> &'static LazyTypeObject<Self>

fn dict_offset() -> Option<PyObjectOffset>

Used to provide the dictoffset slot (equivalent to tp_dictoffset)

fn weaklist_offset() -> Option<PyObjectOffset>

Used to provide the weaklistoffset slot (equivalent to tp_weaklistoffset

impl PyClassNewTextSignature for DataTypeMap

const TEXT_SIGNATURE: &'static str = "(arrow_type, python_type, sql_type)"

impl PyMethods<DataTypeMap> for PyClassImplCollector<DataTypeMap>

fn py_methods(self) -> &'static PyClassItems

impl PyTypeInfo for DataTypeMap

const NAME: &str = <Self as ::pyo3::PyClass>::NAME

👎Deprecated since 0.28.0:

prefer using ::type_object(py).name() to get the correct runtime value

Class name.

const MODULE: Option<&str> = <Self as ::pyo3::impl_::pyclass::PyClassImpl>::MODULE

👎Deprecated since 0.28.0:

prefer using ::type_object(py).module() to get the correct runtime value

Module name, if any.

fn type_object_raw(py: Python<'_>) -> *mut PyTypeObject

Returns the PyTypeObject instance for this type.

fn type_object(py: Python<'_>) -> Bound<'_, PyType>

Returns the safe abstraction over the type object.

fn is_type_of(object: &Bound<'_, PyAny>) -> bool

Checks if object is an instance of this type or a subclass of this type.

fn is_exact_type_of(object: &Bound<'_, PyAny>) -> bool

Checks if object is an instance of this type.