Struct polars_plan::dsl::ListNameSpace

pub struct ListNameSpace(pub Expr);

Specialized expressions for Series of DataType::List.

Tuple Fields

0: Expr

Implementations

impl ListNameSpace

pub fn lengths(self) -> Expr

Get lengths of the arrays in the List type.

pub fn max(self) -> Expr

Compute the maximum of the items in every sublist.

pub fn min(self) -> Expr

Compute the minimum of the items in every sublist.

pub fn sum(self) -> Expr

Compute the sum the items in every sublist.

pub fn mean(self) -> Expr

Compute the mean of every sublist and return a Series of dtype Float64

pub fn sort(self, options: SortOptions) -> Expr

Sort every sublist.

pub fn reverse(self) -> Expr

Reverse every sublist

pub fn unique(self) -> Expr

Keep only the unique values in every sublist.

pub fn get(self, index: Expr) -> Expr

Get items in every sublist by index.

pub fn first(self) -> Expr

Get first item of every sublist.

pub fn last(self) -> Expr

Get last item of every sublist.

pub fn join(self, separator: &str) -> Expr

Join all string items in a sublist and place a separator between them.

Error

This errors if inner type of list != DataType::Utf8.

pub fn arg_min(self) -> Expr

Return the index of the minimal value of every sublist

pub fn arg_max(self) -> Expr

Return the index of the maximum value of every sublist

pub fn diff(self, n: usize, null_behavior: NullBehavior) -> Expr

Available on crate feature diff only.

Diff every sublist.

pub fn shift(self, periods: i64) -> Expr

Shift every sublist.

pub fn slice(self, offset: Expr, length: Expr) -> Expr

Slice every sublist.

pub fn head(self, n: Expr) -> Expr

Get the head of every sublist

pub fn tail(self, n: Expr) -> Expr

Get the tail of every sublist

pub fn to_struct(
    self,
    n_fields: ListToStructWidthStrategy,
    name_generator: Option<NameGenerator>,
    upper_bound: usize
) -> Expr

Available on crate feature list_to_struct only.

Convert this List to a Series of type Struct. The width will be determined according to ListToStructWidthStrategy and the names of the fields determined by the given name_generator.

Schema

A polars [LazyFrame] needs to know the schema at all time. The caller therefore must provide an upper_bound of struct fields that will be set. If this is incorrectly downstream operation may fail. For instance an all().sum() expression will look in the current schema to determine which columns to select.

pub fn contains<E: Into<Expr>>(self, other: E) -> Expr

Available on crate feature is_in only.

Check if the list array contain an element