Enum KeyValueMetadata

pub enum KeyValueMetadata {
    Static(Vec<KeyValue>),
    DynamicRust(RustKeyValueMetadataFunction),
    DynamicPython(PythonKeyValueMetadataFunction),
}

Key/value pairs that can be attached to a Parquet file as file-level metadtaa.

Variants

Static(Vec<KeyValue>)

Static key value metadata.

DynamicRust(RustKeyValueMetadataFunction)

Rust function to dynamically compute key value metadata.

DynamicPython(PythonKeyValueMetadataFunction)

Python function to dynamically compute key value metadata.

Implementations

impl KeyValueMetadata

pub fn from_static(kv: Vec<(String, String)>) -> KeyValueMetadata

Create a key value metadata object from a static key value mapping.

pub fn from_py_function(py_object: Py<PyAny>) -> KeyValueMetadata

Create a key value metadata object from a Python function.

pub fn collect( &self, ctx: ParquetMetadataContext<'_>, ) -> Result<Vec<KeyValue>, PolarsError>

Turn the metadata into the key/value pairs to write to the Parquet file. The context is used to dynamically construct key/value pairs.

Trait Implementations

impl Clone for KeyValueMetadata

fn clone(&self) -> KeyValueMetadata

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for KeyValueMetadata

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for KeyValueMetadata

fn deserialize<__D>( __deserializer: __D, ) -> Result<KeyValueMetadata, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Hash for KeyValueMetadata

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for KeyValueMetadata

fn eq(&self, other: &KeyValueMetadata) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for KeyValueMetadata

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for KeyValueMetadata

impl StructuralPartialEq for KeyValueMetadata