ColumnExpressionSequence

class lsst.daf.relation.ColumnExpressionSequence(items: Sequence[ColumnExpression], dtype: type | None)

Bases: ColumnContainer

A container expression backed by a sequence of scalar column expressions.

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

Methods Documentation

contains(item: ColumnExpression) → ColumnInContainer

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

Parameters:

itemColumnExpression

Item expression to test.

Returns:

containsColumnInContainer

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:

engineEngine

Engine to test.

Returns:

supportedbool

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

classmethod range_literal(r: range) → ColumnRangeLiteral

Construct a container expression from a range of indices.

Parameters:

rrange

Range object.

Returns:

containerColumnRangeLiteral

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:

itemsSequence [ ColumnExpression ]

Sequence of item expressions.

dtypetype, optional

The Python type of the elements in the container.

Returns:

containerColumnExpressionSequence

Container expression object backed by the given items.