CalculationRowIterable¶
- class lsst.daf.relation.iteration.CalculationRowIterable(target: RowIterable, tag: ColumnTag, callable: Callable[[Mapping[ColumnTag, Any]], Any])¶
Bases:
RowIterable
A
RowIterable
implementation that implements a calculation operation.- Parameters:
- target
RowIterable
Original iterable.
- tag
ColumnTag
Key for the new column in result-row mappings.
- callable
Callable
Callable that takes a single mapping argument and returns a new column value.
- target
Methods Summary
Convert this iterable to one that holds its rows in a Python collection of some kind, instead of generating them lazily.
sliced
(start, stop)Apply a slice operation to this
RowIterable
.to_mapping
(unique_key)Convert this iterable to a
RowMapping
, unless it already is one.Convert this iterable to a
RowSequence
, unless it already is one.Methods Documentation
- materialized() MaterializedRowIterable ¶
Convert this iterable to one that holds its rows in a Python collection of some kind, instead of generating them lazily.
- Returns:
- rows
MaterializedRowIterable
A
RowIterable
that isn’t lazy.
- rows
- sliced(start: int, stop: int | None) RowIterable ¶
Apply a slice operation to this
RowIterable
.- Parameters:
- Returns:
- rows
RowIterable
Iterable representing the slice. May or may not be lazy.
- rows
- to_mapping(unique_key: Sequence[ColumnTag]) RowMapping ¶
Convert this iterable to a
RowMapping
, unless it already is one.- Parameters:
- Returns:
- rows
RowMapping
A
RowIterable
backed by a mapping.
- rows
- to_sequence() RowSequence ¶
Convert this iterable to a
RowSequence
, unless it already is one.- Returns:
- rows
RowSequence
A
RowIterable
backed by a sequence.
- rows