Struct perspective_python::Table

pub struct Table(/* private fields */);

Table is Perspective’s columnar data frame, analogous to a Pandas DataFrame or Apache Arrow, supporting append & in-place updates, removal by index, and update notifications.

A Table contains columns, each of which have a unique name, are strongly and consistently typed, and contains rows of data conforming to the column’s type. Each column in a Table must have the same number of rows, though not every row must contain data; null-values are used to indicate missing values in the dataset.

The schema of a Table is immutable after creation, which means the column names and data types cannot be changed after the Table has been created. Columns cannot be added or deleted after creation either, but a View can be used to select an arbitrary set of columns from the Table.

The examples in this module are in JavaScript. See perspective docs for the Rust API.

The examples in this module are in Python. See perspective docs for the Rust API.

Implementations

impl Table

pub fn get_index(&self) -> Option<String>

Returns the name of the index column for the table.

JavaScript Examples

const table = await client.table("x,y\n1,2\n3,4", { index: "x" });
const index = table.get_index(); // "x"

Python Examples

table = client.table("x,y\n1,2\n3,4", index="x");
index = table.get_index() # "x"

Examples

let options = TableInitOptions {index: Some("x".to_string()), ..default() };
let table = client.table("x,y\n1,2\n3,4", options).await;
let tables = client.open_table("table_one").await;

pub fn get_client(&self, loop_cb: Option<Py<PyAny>>) -> Client

Get a copy of the Client this Table came from.

pub fn get_limit(&self) -> Option<u32>

Get a copy of the Client this Table came from.

pub fn get_name(&self) -> String

pub fn clear(&self) -> PyResult<()>

Removes all the rows in the Table, but preserves everything else including the schema, index, and any callbacks or registered View instances.

Calling Table::clear, like Table::update and Table::remove, will trigger an update event to any registered listeners via View::on_update.

pub fn columns(&self) -> PyResult<Vec<String>>

Returns the column names of this Table in “natural” order (the ordering implied by the input format).

JavaScript Examples

const columns = await table.columns();

Python Examples

columns = table.columns()

Examples

let columns = table.columns().await;

pub fn delete(&self) -> PyResult<()>

Delete this Table and cleans up associated resources, assuming it has no View instances registered to it (which must be deleted first).

Tables do not stop consuming resources or processing updates when they are garbage collected in their host language - you must call this method to reclaim these.

JavaScript Examples

const table = await client.table("x,y\n1,2\n3,4");

// ...

await table.delete();

Python Examples

table = client.table("x,y\n1,2\n3,4")

// ...

table.delete()

Examples

let opts = TableInitOptions::default();
let data = TableData::Update(UpdateData::Csv("x,y\n1,2\n3,4".into()));
let table = client.table(data, opts).await?;

// ...

table.delete().await?;

pub fn make_port(&self) -> PyResult<i32>

Create a unique channel ID on this Table, which allows View::on_update callback calls to be associated with the Table::update which caused them.

pub fn on_delete(&self, callback: Py<PyAny>) -> PyResult<u32>

Register a callback which is called exactly once, when this Table is deleted with the Table::delete method.

Table::on_delete resolves when the subscription message is sent, not when the delete event occurs.

pub fn remove(&self, input: Py<PyAny>) -> PyResult<()>

Removes rows from this Table with the index column values supplied.

Arguments

• indices - A list of index column values for rows that should be removed.

JavaScript Examples

await table.remove([1, 2, 3]);

Python Examples

tbl = Table({"a": [1, 2, 3]}, index="a")
tbl.remove([2, 3])

Examples

table.remove(UpdateData::Csv("index\n1\n2\n3")).await?;

pub fn remove_delete(&self, callback_id: u32) -> PyResult<()>

Removes a listener with a given ID, as returned by a previous call to Table::on_delete.

pub fn schema(&self) -> PyResult<HashMap<String, String>>

Returns a table’s Schema, a mapping of column names to column types.

The mapping of a Table’s column names to data types is referred to as a Schema. Each column has a unique name and a data type, one of:

• "boolean" - A boolean type
• "date" - A timesonze-agnostic date type (month/day/year)
• "datetime" - A millisecond-precision datetime type in the UTC timezone
• "float" - A 64 bit float
• "integer" - A signed 32 bit integer (the integer type supported by JavaScript)
• "string" - A String data type (encoded internally as a dictionary)

Note that all Table columns are nullable, regardless of the data type.

pub fn validate_expressions(&self, expression: Py<PyAny>) -> PyResult<Py<PyAny>>

Validates the given expressions.

Python Examples

exprs = client.validate_expressions({"computed": '"Quantity" + 4'})

pub fn view(&self, config: Option<Py<PyDict>>) -> PyResult<View>

Create a new View from this table with a specified ViewConfigUpdate.

See View struct.

JavaScript Examples

const view = await table.view({
    columns: ["Sales"],
    aggregates: { Sales: "sum" },
    group_by: ["Region", "Country"],
    filter: [["Category", "in", ["Furniture", "Technology"]]],
});

Python Examples

view = table.view(
  columns=["Sales"],
  aggregates={"Sales": "sum"},
  group_by=["Region", "Country"],
  filter=[["Category", "in", ["Furniture", "Technology"]]]
)

Examples

use crate::config::*;
let view = table
    .view(Some(ViewConfigUpdate {
        columns: Some(vec![Some("Sales".into())]),
        aggregates: Some(HashMap::from_iter(vec![("Sales".into(), "sum".into())])),
        group_by: Some(vec!["Region".into(), "Country".into()]),
        filter: Some(vec![Filter::new("Category", "in", &[
            "Furniture",
            "Technology",
        ])]),
        ..ViewConfigUpdate::default()
    }))
    .await?;

pub fn size(&self, py: Python<'_>) -> PyResult<usize>

Returns the number of rows in a Table.

pub fn replace(&self, input: Py<PyAny>) -> PyResult<()>

Updates the rows of this table and any derived View instances.

Calling Table::update will trigger the View::on_update callbacks register to derived View, and the call itself will not resolve until all derived View’s are notified.

When updating a Table with an index, Table::update supports partial updates, by omitting columns from the update data.

Arguments

• input - The input data for this Table. The schema of a Table is immutable after creation, so this method cannot be called with a schema.
• options - Options for this update step - see UpdateOptions.

JavaScript Examples

await table.update("x,y\n1,2");

Python Examples

table.update("x,y\n1,2")

Examples

let data = UpdateData::Csv("x,y\n1,2".into());
let opts = UpdateOptions::default();
table.update(data, opts).await?;

pub fn update( &self, py: Python<'_>, input: Py<PyAny>, port_id: Option<u32>, ) -> PyResult<()>

Updates the rows of this table and any derived View instances.

Calling Table::update will trigger the View::on_update callbacks register to derived View, and the call itself will not resolve until all derived View’s are notified.

When updating a Table with an index, Table::update supports partial updates, by omitting columns from the update data.

Arguments

• input - The input data for this Table. The schema of a Table is immutable after creation, so this method cannot be called with a schema.
• options - Options for this update step - see UpdateOptions.

JavaScript Examples

await table.update("x,y\n1,2");

Python Examples

table.update("x,y\n1,2")

Examples

let data = UpdateData::Csv("x,y\n1,2".into());
let opts = UpdateOptions::default();
table.update(data, opts).await?;

Trait Implementations

impl HasPyGilRef for Table

type AsRefTarget = PyCell<Table>

Utility type to make Py::as_ref work.

impl IntoPy<Py<PyAny>> for Table

fn into_py(self, py: Python<'_>) -> PyObject

Performs the conversion.

impl PyClass for Table

type Frozen = False

Whether the pyclass is frozen.

impl PyClassImpl for Table

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)]

type BaseType = PyAny

Base class

type ThreadChecker = SendablePyClass<Table>

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 doc(py: Python<'_>) -> PyResult<&'static CStr>

Rendered class doc

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

fn dict_offset() -> Option<isize>

fn weaklist_offset() -> Option<isize>

impl<'a, 'py> PyFunctionArgument<'a, 'py> for &'a Table

type Holder = Option<PyRef<'py, Table>>

fn extract( obj: &'a Bound<'py, PyAny>, holder: &'a mut Self::Holder, ) -> PyResult<Self>

impl<'a, 'py> PyFunctionArgument<'a, 'py> for &'a mut Table

type Holder = Option<PyRefMut<'py, Table>>

fn extract( obj: &'a Bound<'py, PyAny>, holder: &'a mut Self::Holder, ) -> PyResult<Self>

impl PyMethods<Table> for PyClassImplCollector<Table>

fn py_methods(self) -> &'static PyClassItems

impl PyTypeInfo for Table

const NAME: &'static str = "Table"

Class name.

const MODULE: Option<&'static str> = ::core::option::Option::None

Module name, if any.

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

Returns the PyTypeObject instance for this type.

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

👎Deprecated since 0.21.0: PyTypeInfo::type_object will be replaced by PyTypeInfo::type_object_bound in a future PyO3 version

Returns the safe abstraction over the type object.

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

Returns the safe abstraction over the type object.

fn is_type_of(object: &PyAny) -> bool

👎Deprecated since 0.21.0: PyTypeInfo::is_type_of will be replaced by PyTypeInfo::is_type_of_bound in a future PyO3 version

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

fn is_type_of_bound(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: &PyAny) -> bool

👎Deprecated since 0.21.0: PyTypeInfo::is_exact_type_of will be replaced by PyTypeInfo::is_exact_type_of_bound in a future PyO3 version

Checks if object is an instance of this type.

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

Checks if object is an instance of this type.

impl DerefToPyAny for Table