Enum Expr 

pub enum Expr {
    Column(String),
    Literal(Scalar),
    BinaryOp {
        left: Box<Expr>,
        op: Operator,
        right: Box<Expr>,
    },
    UnaryOp {
        op: UnaryOperator,
        expr: Box<Expr>,
    },
    Agg {
        func: AggFunc,
        expr: Box<Expr>,
    },
    Alias {
        expr: Box<Expr>,
        name: String,
    },
    Wildcard,
}

Expression AST and supporting enums. Expression AST used by DataFrame and LazyFrame.

Variants

Column(String)

Column reference.

Literal(Scalar)

Literal scalar value.

BinaryOp

Binary operator expression.

Fields

left: Box<Expr>

op: Operator

right: Box<Expr>

UnaryOp

Unary operator expression.

Fields

op: UnaryOperator

expr: Box<Expr>

Agg

Aggregation expression (only valid under group_by().agg()).

Fields

func: AggFunc

expr: Box<Expr>

Alias

Expression alias (renames the resulting column).

Fields

expr: Box<Expr>

name: String

Wildcard

Wildcard (*) that expands to all columns in projections.

Implementations

impl Expr

pub fn alias(self, name: impl Into<String>) -> Expr

Alias this expression (used to name output columns).

pub fn add(self, rhs: Expr) -> Expr

Build an addition expression.

pub fn sub(self, rhs: Expr) -> Expr

Build a subtraction expression.

pub fn mul(self, rhs: Expr) -> Expr

Build a multiplication expression.

pub fn div(self, rhs: Expr) -> Expr

Build a division expression.

pub fn eq(self, rhs: Expr) -> Expr

Build an equality predicate.

pub fn neq(self, rhs: Expr) -> Expr

Build an inequality predicate.

pub fn gt(self, rhs: Expr) -> Expr

Build a greater-than predicate.

pub fn lt(self, rhs: Expr) -> Expr

Build a less-than predicate.

pub fn ge(self, rhs: Expr) -> Expr

Build a greater-than-or-equal predicate.

pub fn le(self, rhs: Expr) -> Expr

Build a less-than-or-equal predicate.

pub fn and_(self, rhs: Expr) -> Expr

Build a boolean AND predicate.

pub fn or_(self, rhs: Expr) -> Expr

Build a boolean OR predicate.

pub fn not_(self) -> Expr

Build a boolean NOT predicate.

pub fn sum(self) -> Expr

Build a sum aggregation.

pub fn mean(self) -> Expr

Build a mean aggregation.

pub fn count(self) -> Expr

Build a count aggregation (nulls excluded).

pub fn min(self) -> Expr

Build a min aggregation.

pub fn max(self) -> Expr

Build a max aggregation.

Trait Implementations

impl Clone for Expr

fn clone(&self) -> Expr

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Expr

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for Expr

fn eq(&self, other: &Expr) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Expr