ColumnRangeLiteral

class lsst.daf.relation.ColumnRangeLiteral(value: range, dtype: type = <class 'int'>)

Bases: lsst.daf.relation.ColumnContainer

A container expression backed by a range of integer indices.

Attributes Summary

columns_required Columns required by this expression (Set [ ColumnTag ]).

Methods Summary

contains(item) Construct a boolean column expression that tests whether a scalar expression is present in this container expression.
is_supported_by(engine) Test whether the given engine is capable of evaluating this expression.
range_literal(r) Construct a container expression from a range of indices.
sequence(items, dtype) Construct a container expression from a sequence of item expressions.

Attributes Documentation

columns_required

Columns required by this expression (Set [ ColumnTag ]).

This includes columns required by expressions nested within this one.

Methods Documentation

contains(item: ColumnExpression) → ColumnInContainer

Construct a boolean column expression that tests whether a scalar expression is present in this container expression.

Parameters:
item : ColumnExpression

Item expression to test.

Returns:
contains : ColumnInContainer

Boolean column expression that tests for membership in the container.

is_supported_by(engine: Engine) → bool

Test whether the given engine is capable of evaluating this expression.

Parameters:
engine : Engine

Engine to test.

Returns:
supported : bool

Whether the engine supports this expression and all expressions nested within it.

classmethod range_literal(r: range) → lsst.daf.relation._columns._container.ColumnRangeLiteral

Construct a container expression from a range of indices.

Parameters:
r : range

Range object.

Returns:
container : ColumnRangeLiteral

Container expression object representing the range.

classmethod sequence(items: Sequence[ColumnExpression], dtype: type | None = None) → ColumnExpressionSequence

Construct a container expression from a sequence of item expressions.

Parameters:
items : Sequence [ ColumnExpression ]

Sequence of item expressions.

dtype : type, optional

The Python type of the elements in the container.

Returns:
container : ColumnExpressionSequence

Container expression object backed by the given items.