UnnestExpr

class ray.data.expressions.UnnestExpr(expr: Expr)

Bases: Expr

Expression that expands a struct-typed expression into one output column per struct field.

This is a plan-time marker, analogous to StarExpr: it never survives into the optimizer or the evaluation engine. Project.__post_init__ eagerly desugars it (via expand_projection) into one expr.struct.field_by_index(i).alias(field_name) projection entry per struct field, so downstream code only ever sees ordinary named expressions. The struct field names and order come from the expression’s resolved PyArrow struct type; CommonSubExprElimination then deduplicates the shared inner subtree so it is evaluated once per block.

Because desugaring needs the struct type at plan time, the wrapped expression must either carry a declared struct return_dtype (UDFs) or reference a struct column resolvable from the input schema. Otherwise Project construction raises.

See unnest() for the public constructor.

DeveloperAPI: This API may change across minor Ray releases.

Methods

abs	Compute the absolute value of the expression.
acos	Compute the arccosine (inverse cosine) of the expression, returning radians.
asin	Compute the arcsine (inverse sine) of the expression, returning radians.
atan	Compute the arctangent (inverse tangent) of the expression, returning radians.
cast	Cast the expression to a specified type.
ceil	Round values up to the nearest integer.
cos	Compute the cosine of the expression (in radians).
exp	Compute the natural exponential of the expression.
expand_projection	Desugar into one aliased struct-field access per struct field.
floor	Round values down to the nearest integer.
get_type	Resolve the output PyArrow data type given the input schema.
is_idempotent	Return whether this expression is safe to duplicate, reorder, or move.
is_in	Check if the expression value is in a list of values.
is_not_null	Check if the expression value is not null.
is_null	Check if the expression value is null.
ln	Compute the natural logarithm of the expression.
log10	Compute the base-10 logarithm of the expression.
log2	Compute the base-2 logarithm of the expression.
negate	Compute the negation of the expression.
not_in	Check if the expression value is not in a list of values.
nullable	Whether the output of this expression may contain nulls.
power	Raise the expression to the given power.
round	Round values to the nearest integer using PyArrow semantics.
sign	Compute the sign of the expression.
sin	Compute the sine of the expression (in radians).
tan	Compute the tangent of the expression (in radians).
to_pyarrow	Convert this Ray Data expression to a PyArrow compute expression.
trunc	Truncate fractional values toward zero.

Attributes

arr	Access array operations for this expression.
dt	Access datetime operations for this expression.
list	Access list operations for this expression.
map	Access map/dict operations for this expression.
name	Get the name associated with this expression.
str	Access string operations for this expression.
struct	Access struct operations for this expression.
expr	The wrapped expression; must resolve to a PyArrow struct type.
data_type