Class Expr<T, N>

Static value type of an expression (T) and its output column name (N, set by alias). Both are phantom: col('x') is Expr<any> (nothing is known about a column named by string), c.x from a typed frame's column refs is Expr<S['x'], 'x'>, comparisons produce Expr<boolean>, arithmetic Expr<number>. Frames use them to type filter, withColumn(s), select and agg results.

Type Parameters

T = any
N extends string = string

Index

Methods

Constructors

constructor

new Expr<T = any, N extends string = string>(node: ExprNode): Expr<T, N>
Type Parameters
- T = any
- N extends string = string
Parameters
- node: ExprNode
Returns Expr<T, N>
- Defined in core/dist/index.d.ts:56

Properties

`Readonly`node

node: ExprNode

Accessors

dt

get dt(): DtNamespace
Returns DtNamespace
- Defined in core/dist/index.d.ts:58

str

get str(): StrNamespace
Returns StrNamespace
- Defined in core/dist/index.d.ts:57

Methods

abs

abs(): Expr<number, N>
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:65

add

add(other: number | AnyExpr): Expr<number, N>
Parameters
- other: number | AnyExpr
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:87

alias

alias<M extends string>(name: M): Expr<T, M>
Type Parameters
- M extends string
Parameters
- name: M
Returns Expr<T, M>
- Defined in core/dist/index.d.ts:59

and

and(other: boolean | AnyExpr): Expr<boolean, N>
Parameters
- other: boolean | AnyExpr
Returns Expr<boolean, N>
- Defined in core/dist/index.d.ts:85

asc

asc(
options?: { nullsLast?: boolean },
): { descending: boolean; expr: Expr<T, N>; nullsLast?: boolean }
Parameters
- Optionaloptions: { nullsLast?: boolean }
Returns { descending: boolean; expr: Expr<T, N>; nullsLast?: boolean }
- Defined in core/dist/index.d.ts:132

cast

cast<D extends DType>(dtype: D): Expr<DTypeValue<D>, N>
Type Parameters
- D extends DType
Parameters
- dtype: D
Returns Expr<DTypeValue<D>, N>
- Defined in core/dist/index.d.ts:60

ceil

ceil(): Expr<number, N>
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:76

clip

clip(min?: number, max?: number): Expr<T, N>
Parameters
- Optionalmin: number
- Optionalmax: number
Returns Expr<T, N>
- Defined in core/dist/index.d.ts:94

count

count(): Expr<number, N>
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:103

desc

desc(
options?: { nullsLast?: boolean },
): { descending: boolean; expr: Expr<T, N>; nullsLast?: boolean }
Parameters
- Optionaloptions: { nullsLast?: boolean }
Returns { descending: boolean; expr: Expr<T, N>; nullsLast?: boolean }
- Defined in core/dist/index.d.ts:139

diff

diff(periods?: number): Expr<number | null, N>
Parameters
- Optionalperiods: number
Returns Expr<number | null, N>
- Defined in core/dist/index.d.ts:96

div

div(other: number | AnyExpr): Expr<number, N>
Parameters
- other: number | AnyExpr
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:90

eq

eq(other: string | number | boolean | AnyExpr | null): Expr<boolean, N>
Parameters
- other: string | number | boolean | AnyExpr | null
Returns Expr<boolean, N>
- Defined in core/dist/index.d.ts:79

exp

exp(): Expr<number, N>
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:72

fillNull

fillNull<V extends string | number | boolean>(
value: V,
): Expr<V | Exclude<T, null>, N>
Type Parameters
- V extends string | number | boolean
Parameters
- value: V
Returns Expr<V | Exclude<T, null>, N>
- Defined in core/dist/index.d.ts:61

first

first(): Expr<T, N>
Returns Expr<T, N>
- Defined in core/dist/index.d.ts:105

floor

floor(): Expr<number, N>
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:75

gt

gt(other: string | number | boolean | AnyExpr | null): Expr<boolean, N>
Parameters
- other: string | number | boolean | AnyExpr | null
Returns Expr<boolean, N>
- Defined in core/dist/index.d.ts:81

gte

gte(other: string | number | boolean | AnyExpr | null): Expr<boolean, N>
Parameters
- other: string | number | boolean | AnyExpr | null
Returns Expr<boolean, N>
- Defined in core/dist/index.d.ts:82

isBetween

isBetween(
    low: string | number | AnyExpr,
    high: string | number | AnyExpr,
    closed?: "left" | "right" | "both" | "neither",
): Expr<boolean, N>
Parameters
- low: string | number | AnyExpr
- high: string | number | AnyExpr
- Optionalclosed: "left" | "right" | "both" | "neither"
Returns Expr<boolean, N>
- Defined in core/dist/index.d.ts:93

isIn

isIn(values: (string | number | boolean | null)[]): Expr<boolean, N>
Parameters
- values: (string | number | boolean | null)[]
Returns Expr<boolean, N>
- Defined in core/dist/index.d.ts:92

isNotNull

isNotNull(): Expr<boolean, N>
Returns Expr<boolean, N>
- Defined in core/dist/index.d.ts:63

isNull

isNull(): Expr<boolean, N>
Returns Expr<boolean, N>
- Defined in core/dist/index.d.ts:62

last

last(): Expr<T, N>
Returns Expr<T, N>
- Defined in core/dist/index.d.ts:106

log

log(base?: number): Expr<number, N>
Natural log by default; pass base for log_b (e.g. log(10)).
Parameters
- Optionalbase: number
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:69

log10

log10(): Expr
Returns Expr
- Defined in core/dist/index.d.ts:70

log2

log2(): Expr
Returns Expr
- Defined in core/dist/index.d.ts:71

lt

lt(other: string | number | boolean | AnyExpr | null): Expr<boolean, N>
Parameters
- other: string | number | boolean | AnyExpr | null
Returns Expr<boolean, N>
- Defined in core/dist/index.d.ts:83

lte

lte(other: string | number | boolean | AnyExpr | null): Expr<boolean, N>
Parameters
- other: string | number | boolean | AnyExpr | null
Returns Expr<boolean, N>
- Defined in core/dist/index.d.ts:84

mapElements

mapElements<R extends string | number | boolean | null>(
fn: (value: string | number | boolean | null) => R,
): Expr<R, N>
Type Parameters
- R extends string | number | boolean | null
Parameters
- fn: (value: string | number | boolean | null) => R
Returns Expr<R, N>
- Defined in core/dist/index.d.ts:98

max

max(): Expr<T, N>
Returns Expr<T, N>
- Defined in core/dist/index.d.ts:102

mean

mean(): Expr<number, N>
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:100

median

median(method?: QuantileMethod): Expr<number, N>
Median. method: 'linear' (default; type 7, pandas / polars) or 'minitab' (type 6, position p(n + 1)) — both give the middle value / midpoint for the median, the choice matters for other quantiles.
Parameters
- Optionalmethod: QuantileMethod
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:113

min

min(): Expr<T, N>
Returns Expr<T, N>
- Defined in core/dist/index.d.ts:101

mod

mod(other: number | AnyExpr): Expr<number, N>
Parameters
- other: number | AnyExpr
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:91

mul

mul(other: number | AnyExpr): Expr<number, N>
Parameters
- other: number | AnyExpr
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:89

neg

neg(): Expr<number, N>
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:66

neq

neq(other: string | number | boolean | AnyExpr | null): Expr<boolean, N>
Parameters
- other: string | number | boolean | AnyExpr | null
Returns Expr<boolean, N>
- Defined in core/dist/index.d.ts:80

not

not(): Expr<boolean, N>
Returns Expr<boolean, N>
- Defined in core/dist/index.d.ts:64

nunique

nunique(): Expr<number, N>
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:104

or

or(other: boolean | AnyExpr): Expr<boolean, N>
Parameters
- other: boolean | AnyExpr
Returns Expr<boolean, N>
- Defined in core/dist/index.d.ts:86

over

over(
partitionBy: string | string[],
options?: { descending?: boolean; orderBy?: string | string[] },
): Expr<T, N>
Window: aggregates inside this expression are computed per partition and broadcast back to each row of the partition (polars over, SQL … OVER (PARTITION BY …)). col('x').mean().over('g') // group mean on every row col('x').sub(col('x').mean()).over('g') // deviation from own group's mean col('x').div(col('x').sum().over(['a', 'b'])) // share within (a, b)
Parameters
- partitionBy: string | string[]
- Optionaloptions: { descending?: boolean; orderBy?: string | string[] }
  - Optionaldescending?: boolean
  - OptionalorderBy?: string | string[]
    
    Running (cumulative) aggregates in this row order — SQL OVER (PARTITION BY … ORDER BY …) / polars cum_sum().over().
Returns Expr<T, N>
- Defined in core/dist/index.d.ts:127

pctChange

pctChange(periods?: number): Expr<number | null, N>
Parameters
- Optionalperiods: number
Returns Expr<number | null, N>
- Defined in core/dist/index.d.ts:97

pow

pow(other: number | AnyExpr): Expr<number, N>
Parameters
- other: number | AnyExpr
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:78

quantile

quantile(q: number, method?: QuantileMethod): Expr<number, N>
Sample quantile q ∈ [0, 1]. col('x').quantile(0.25) // type 7: position (n − 1)q, linear interpolation (pandas default) col('x').quantile(0.25, 'minitab') // type 6: position q(n + 1), clamped to the sample — Minitab / SPSS / R type=6
Parameters
- q: number
- Optionalmethod: QuantileMethod
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:119

round

round(decimals?: number): Expr<number, N>
Round half away from zero (Minitab / Excel ROUND) to decimals places.
Parameters
- Optionaldecimals: number
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:74

shift

shift(periods?: number): Expr<T | null, N>
Parameters
- Optionalperiods: number
Returns Expr<T | null, N>
- Defined in core/dist/index.d.ts:95

sign

sign(): Expr<number, N>
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:77

sqrt

sqrt(): Expr<number, N>
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:67

std

std(): Expr<number, N>
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:107

sub

sub(other: number | AnyExpr): Expr<number, N>
Parameters
- other: number | AnyExpr
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:88

sum

sum(): Expr<number, N>
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:99

var

var(): Expr<number, N>
Returns Expr<number, N>
- Defined in core/dist/index.d.ts:108

Class Expr<T, N>

Type Parameters

Index

Constructors

Properties

Accessors

Methods

Constructors

constructor

Type Parameters

Parameters

Returns Expr<T, N>

Properties

Readonlynode

Accessors

dt

Returns DtNamespace

str

Returns StrNamespace

Methods

abs

Returns Expr<number, N>

add

Parameters

Returns Expr<number, N>

alias

Type Parameters

Parameters

Returns Expr<T, M>

and

Parameters

Returns Expr<boolean, N>

asc

Parameters

Returns { descending: boolean; expr: Expr<T, N>; nullsLast?: boolean }

cast

Type Parameters

Parameters

Returns Expr<DTypeValue<D>, N>

ceil

Returns Expr<number, N>

clip

Parameters

Returns Expr<T, N>

count

Returns Expr<number, N>

desc

Parameters

Returns { descending: boolean; expr: Expr<T, N>; nullsLast?: boolean }

diff

Parameters

Returns Expr<number | null, N>

div

Parameters

Returns Expr<number, N>

eq

Parameters

Returns Expr<boolean, N>

exp

Returns Expr<number, N>

fillNull

Type Parameters

Parameters

Returns Expr<V | Exclude<T, null>, N>

first

Returns Expr<T, N>

floor

Returns Expr<number, N>

gt

Parameters

Returns Expr<boolean, N>

gte

Parameters

Returns Expr<boolean, N>

isBetween

Parameters

Returns Expr<boolean, N>

isIn

Parameters

Returns Expr<boolean, N>

`Readonly`node

`Optional`descending?: boolean

`Optional`orderBy?: string | string[]