pub enum Expr {
Show 28 variants
Alias(Arc<Expr>, PlSmallStr),
Column(PlSmallStr),
Columns(Arc<[PlSmallStr]>),
DtypeColumn(Vec<DataType>),
IndexColumn(Arc<[i64]>),
Literal(LiteralValue),
BinaryExpr {
left: Arc<Expr>,
op: Operator,
right: Arc<Expr>,
},
Cast {
expr: Arc<Expr>,
dtype: DataType,
options: CastOptions,
},
Sort {
expr: Arc<Expr>,
options: SortOptions,
},
Gather {
expr: Arc<Expr>,
idx: Arc<Expr>,
returns_scalar: bool,
},
SortBy {
expr: Arc<Expr>,
by: Vec<Expr>,
sort_options: SortMultipleOptions,
},
Agg(AggExpr),
Ternary {
predicate: Arc<Expr>,
truthy: Arc<Expr>,
falsy: Arc<Expr>,
},
Function {
input: Vec<Expr>,
function: FunctionExpr,
options: FunctionOptions,
},
Explode(Arc<Expr>),
Filter {
input: Arc<Expr>,
by: Arc<Expr>,
},
Window {
function: Arc<Expr>,
partition_by: Vec<Expr>,
order_by: Option<(Arc<Expr>, SortOptions)>,
options: WindowType,
},
Wildcard,
Slice {
input: Arc<Expr>,
offset: Arc<Expr>,
length: Arc<Expr>,
},
Exclude(Arc<Expr>, Vec<Excluded>),
KeepName(Arc<Expr>),
Len,
Nth(i64),
RenameAlias {
function: SpecialEq<Arc<dyn RenameAliasFn>>,
expr: Arc<Expr>,
},
Field(Arc<[PlSmallStr]>),
AnonymousFunction {
input: Vec<Expr>,
function: LazySerde<SpecialEq<Arc<dyn ColumnsUdf>>>,
output_type: SpecialEq<Arc<dyn FunctionOutputField>>,
options: FunctionOptions,
},
SubPlan(SpecialEq<Arc<DslPlan>>, Vec<String>),
Selector(Selector),
}
Expand description
Expressions that can be used in various contexts.
Queries consist of multiple expressions.
When using the polars lazy API, don’t construct an Expr
directly; instead, create one using
the functions in the polars_lazy::dsl
module. See that module’s docs for more info.
Variants§
Alias(Arc<Expr>, PlSmallStr)
Column(PlSmallStr)
Columns(Arc<[PlSmallStr]>)
DtypeColumn(Vec<DataType>)
IndexColumn(Arc<[i64]>)
Literal(LiteralValue)
BinaryExpr
Cast
Sort
Gather
SortBy
Agg(AggExpr)
Ternary
A ternary operation if true then “foo” else “bar”
Function
Explode(Arc<Expr>)
Filter
Window
Polars flavored window functions.
Wildcard
Slice
Fields
Exclude(Arc<Expr>, Vec<Excluded>)
Can be used in a select statement to exclude a column from selection
TODO: See if we can replace Vec<Excluded>
with Arc<Excluded>
KeepName(Arc<Expr>)
Set root name as Alias
Len
Nth(i64)
Take the nth column in the DataFrame
RenameAlias
Field(Arc<[PlSmallStr]>)
dtype-struct
only.AnonymousFunction
Fields
function: LazySerde<SpecialEq<Arc<dyn ColumnsUdf>>>
function to apply
output_type: SpecialEq<Arc<dyn FunctionOutputField>>
output dtype of the function
options: FunctionOptions
SubPlan(SpecialEq<Arc<DslPlan>>, Vec<String>)
Selector(Selector)
Expressions in this node should only be expanding
e.g.
Expr::Columns
Expr::Dtypes
Expr::Wildcard
Expr::Exclude
Implementations§
Source§impl Expr
impl Expr
Sourcepub fn cos(self) -> Expr
Available on crate feature trigonometry
only.
pub fn cos(self) -> Expr
trigonometry
only.Compute the cosine of the given expression
Sourcepub fn cot(self) -> Expr
Available on crate feature trigonometry
only.
pub fn cot(self) -> Expr
trigonometry
only.Compute the cotangent of the given expression
Sourcepub fn sin(self) -> Expr
Available on crate feature trigonometry
only.
pub fn sin(self) -> Expr
trigonometry
only.Compute the sine of the given expression
Sourcepub fn tan(self) -> Expr
Available on crate feature trigonometry
only.
pub fn tan(self) -> Expr
trigonometry
only.Compute the tangent of the given expression
Sourcepub fn arccos(self) -> Expr
Available on crate feature trigonometry
only.
pub fn arccos(self) -> Expr
trigonometry
only.Compute the inverse cosine of the given expression
Sourcepub fn arcsin(self) -> Expr
Available on crate feature trigonometry
only.
pub fn arcsin(self) -> Expr
trigonometry
only.Compute the inverse sine of the given expression
Sourcepub fn arctan(self) -> Expr
Available on crate feature trigonometry
only.
pub fn arctan(self) -> Expr
trigonometry
only.Compute the inverse tangent of the given expression
Sourcepub fn arctan2(self, x: Expr) -> Expr
Available on crate feature trigonometry
only.
pub fn arctan2(self, x: Expr) -> Expr
trigonometry
only.Compute the inverse tangent of the given expression, with the angle expressed as the argument of a complex number
Sourcepub fn cosh(self) -> Expr
Available on crate feature trigonometry
only.
pub fn cosh(self) -> Expr
trigonometry
only.Compute the hyperbolic cosine of the given expression
Sourcepub fn sinh(self) -> Expr
Available on crate feature trigonometry
only.
pub fn sinh(self) -> Expr
trigonometry
only.Compute the hyperbolic sine of the given expression
Sourcepub fn tanh(self) -> Expr
Available on crate feature trigonometry
only.
pub fn tanh(self) -> Expr
trigonometry
only.Compute the hyperbolic tangent of the given expression
Sourcepub fn arccosh(self) -> Expr
Available on crate feature trigonometry
only.
pub fn arccosh(self) -> Expr
trigonometry
only.Compute the inverse hyperbolic cosine of the given expression
Sourcepub fn arcsinh(self) -> Expr
Available on crate feature trigonometry
only.
pub fn arcsinh(self) -> Expr
trigonometry
only.Compute the inverse hyperbolic sine of the given expression
Sourcepub fn arctanh(self) -> Expr
Available on crate feature trigonometry
only.
pub fn arctanh(self) -> Expr
trigonometry
only.Compute the inverse hyperbolic tangent of the given expression
Sourcepub fn degrees(self) -> Expr
Available on crate feature trigonometry
only.
pub fn degrees(self) -> Expr
trigonometry
only.Convert from radians to degrees
Source§impl Expr
impl Expr
Sourcepub fn eq_missing<E>(self, other: E) -> Expr
pub fn eq_missing<E>(self, other: E) -> Expr
Compare Expr
with other Expr
on equality where None == None
.
Sourcepub fn neq_missing<E>(self, other: E) -> Expr
pub fn neq_missing<E>(self, other: E) -> Expr
Compare Expr
with other Expr
on non-equality where None == None
.
Sourcepub fn alias<S>(self, name: S) -> Exprwhere
S: Into<PlSmallStr>,
pub fn alias<S>(self, name: S) -> Exprwhere
S: Into<PlSmallStr>,
Rename Column.
Sourcepub fn is_not_null(self) -> Expr
pub fn is_not_null(self) -> Expr
Run is_not_null operation on Expr
.
Sourcepub fn drop_nulls(self) -> Expr
pub fn drop_nulls(self) -> Expr
Drop null values.
Sourcepub fn quantile(self, quantile: Expr, method: QuantileMethod) -> Expr
pub fn quantile(self, quantile: Expr, method: QuantileMethod) -> Expr
Compute the quantile per group.
Sourcepub fn agg_groups(self) -> Expr
pub fn agg_groups(self) -> Expr
Get the group indexes of the group by operation.
Sourcepub fn slice<E, F>(self, offset: E, length: F) -> Expr
pub fn slice<E, F>(self, offset: E, length: F) -> Expr
Slice the Series.
offset
may be negative.
Sourcepub fn append<E>(self, other: E, upcast: bool) -> Expr
pub fn append<E>(self, other: E, upcast: bool) -> Expr
Append expressions. This is done by adding the chunks of other
to this Series
.
Sourcepub fn unique_stable(self) -> Expr
pub fn unique_stable(self) -> Expr
Get unique values of this expression, while maintaining order.
This requires more work than Expr::unique
.
Sourcepub fn arg_unique(self) -> Expr
pub fn arg_unique(self) -> Expr
Get the first index of unique values of this expression.
Sourcepub fn arg_sort(self, sort_options: SortOptions) -> Expr
pub fn arg_sort(self, sort_options: SortOptions) -> Expr
Get the index values that would sort this expression.
Sourcepub fn search_sorted<E>(self, element: E, side: SearchSortedSide) -> Expr
Available on crate feature search_sorted
only.
pub fn search_sorted<E>(self, element: E, side: SearchSortedSide) -> Expr
search_sorted
only.Find indices where elements should be inserted to maintain order.
Sourcepub fn strict_cast(self, dtype: DataType) -> Expr
pub fn strict_cast(self, dtype: DataType) -> Expr
Cast expression to another data type. Throws an error if conversion had overflows. Returns an Error if cast is invalid on rows after predicates are pushed down.
Sourcepub fn cast_with_options(
self,
dtype: DataType,
cast_options: CastOptions,
) -> Expr
pub fn cast_with_options( self, dtype: DataType, cast_options: CastOptions, ) -> Expr
Cast expression to another data type.
Sourcepub fn sort(self, options: SortOptions) -> Expr
pub fn sort(self, options: SortOptions) -> Expr
Sort with given options.
§Example
let lf = df! {
"a" => [Some(5), Some(4), Some(3), Some(2), None]
}?
.lazy();
let sorted = lf
.select(
vec![col("a").sort(SortOptions::default())],
)
.collect()?;
assert_eq!(
sorted,
df! {
"a" => [None, Some(2), Some(3), Some(4), Some(5)]
}?
);
See SortOptions
for more options.
Sourcepub fn top_k(self, k: Expr) -> Expr
Available on crate feature top_k
only.
pub fn top_k(self, k: Expr) -> Expr
top_k
only.Returns the k
largest elements.
This has time complexity O(n + k log(n))
.
Sourcepub fn top_k_by<K, E, IE>(self, k: K, by: E, descending: Vec<bool>) -> Expr
Available on crate feature top_k
only.
pub fn top_k_by<K, E, IE>(self, k: K, by: E, descending: Vec<bool>) -> Expr
top_k
only.Returns the k
largest rows by given column.
For single column, use Expr::top_k
.
Sourcepub fn bottom_k(self, k: Expr) -> Expr
Available on crate feature top_k
only.
pub fn bottom_k(self, k: Expr) -> Expr
top_k
only.Returns the k
smallest elements.
This has time complexity O(n + k log(n))
.
Sourcepub fn bottom_k_by<K, E, IE>(self, k: K, by: E, descending: Vec<bool>) -> Expr
Available on crate feature top_k
only.
pub fn bottom_k_by<K, E, IE>(self, k: K, by: E, descending: Vec<bool>) -> Expr
top_k
only.Returns the k
smallest rows by given column.
For single column, use Expr::bottom_k
.
Sourcepub fn map<F>(
self,
function: F,
output_type: SpecialEq<Arc<dyn FunctionOutputField>>,
) -> Expr
pub fn map<F>( self, function: F, output_type: SpecialEq<Arc<dyn FunctionOutputField>>, ) -> Expr
Apply a function/closure once the logical plan get executed.
This function is very similar to Expr::apply
, but differs in how it handles aggregations.
map
should be used for operations that are independent of groups, e.g.multiply * 2
, orraise to the power
apply
should be used for operations that work on a group of data. e.g.sum
,count
, etc.
It is the responsibility of the caller that the schema is correct by giving the correct output_type. If None given the output type of the input expr is used.
Sourcepub fn map_many<F>(
self,
function: F,
arguments: &[Expr],
output_type: SpecialEq<Arc<dyn FunctionOutputField>>,
) -> Expr
pub fn map_many<F>( self, function: F, arguments: &[Expr], output_type: SpecialEq<Arc<dyn FunctionOutputField>>, ) -> Expr
Sourcepub fn map_list<F>(
self,
function: F,
output_type: SpecialEq<Arc<dyn FunctionOutputField>>,
) -> Expr
pub fn map_list<F>( self, function: F, output_type: SpecialEq<Arc<dyn FunctionOutputField>>, ) -> Expr
Apply a function/closure once the logical plan get executed.
This function is very similar to apply, but differs in how it handles aggregations.
map
should be used for operations that are independent of groups, e.g.multiply * 2
, orraise to the power
apply
should be used for operations that work on a group of data. e.g.sum
,count
, etc.map_list
should be used when the function expects a list aggregated series.
Sourcepub fn function_with_options<F>(
self,
function: F,
output_type: SpecialEq<Arc<dyn FunctionOutputField>>,
options: FunctionOptions,
) -> Expr
pub fn function_with_options<F>( self, function: F, output_type: SpecialEq<Arc<dyn FunctionOutputField>>, options: FunctionOptions, ) -> Expr
A function that cannot be expressed with map
or apply
and requires extra settings.
Sourcepub fn apply<F>(
self,
function: F,
output_type: SpecialEq<Arc<dyn FunctionOutputField>>,
) -> Expr
pub fn apply<F>( self, function: F, output_type: SpecialEq<Arc<dyn FunctionOutputField>>, ) -> Expr
Apply a function/closure over the groups. This should only be used in a group_by aggregation.
It is the responsibility of the caller that the schema is correct by giving the correct output_type. If None given the output type of the input expr is used.
This difference with map is that apply
will create a separate Series
per group.
map
should be used for operations that are independent of groups, e.g.multiply * 2
, orraise to the power
apply
should be used for operations that work on a group of data. e.g.sum
,count
, etc.
Sourcepub fn apply_many<F>(
self,
function: F,
arguments: &[Expr],
output_type: SpecialEq<Arc<dyn FunctionOutputField>>,
) -> Expr
pub fn apply_many<F>( self, function: F, arguments: &[Expr], output_type: SpecialEq<Arc<dyn FunctionOutputField>>, ) -> Expr
Apply a function/closure over the groups with many arguments. This should only be used in a group_by aggregation.
See the Expr::apply
function for the differences between map
and apply
.
pub fn apply_many_private( self, function_expr: FunctionExpr, arguments: &[Expr], returns_scalar: bool, cast_to_supertypes: bool, ) -> Expr
pub fn map_many_private( self, function_expr: FunctionExpr, arguments: &[Expr], returns_scalar: bool, cast_to_supertypes: Option<SuperTypeOptions>, ) -> Expr
Sourcepub fn is_infinite(self) -> Expr
pub fn is_infinite(self) -> Expr
Get mask of infinite values if dtype is Float.
Sourcepub fn is_not_nan(self) -> Expr
pub fn is_not_nan(self) -> Expr
Get inverse mask of NaN values if dtype is Float.
Sourcepub fn shift(self, n: Expr) -> Expr
pub fn shift(self, n: Expr) -> Expr
Shift the values in the array by some period. See the eager implementation.
Sourcepub fn shift_and_fill<E, IE>(self, n: E, fill_value: IE) -> Expr
pub fn shift_and_fill<E, IE>(self, n: E, fill_value: IE) -> Expr
Shift the values in the array by some period and fill the resulting empty values.
Sourcepub fn cum_count(self, reverse: bool) -> Expr
Available on crate feature cum_agg
only.
pub fn cum_count(self, reverse: bool) -> Expr
cum_agg
only.Cumulatively count values from 0 to len.
Sourcepub fn cum_sum(self, reverse: bool) -> Expr
Available on crate feature cum_agg
only.
pub fn cum_sum(self, reverse: bool) -> Expr
cum_agg
only.Get an array with the cumulative sum computed at every element.
Sourcepub fn cum_prod(self, reverse: bool) -> Expr
Available on crate feature cum_agg
only.
pub fn cum_prod(self, reverse: bool) -> Expr
cum_agg
only.Get an array with the cumulative product computed at every element.
Sourcepub fn cum_min(self, reverse: bool) -> Expr
Available on crate feature cum_agg
only.
pub fn cum_min(self, reverse: bool) -> Expr
cum_agg
only.Get an array with the cumulative min computed at every element.
Sourcepub fn cum_max(self, reverse: bool) -> Expr
Available on crate feature cum_agg
only.
pub fn cum_max(self, reverse: bool) -> Expr
cum_agg
only.Get an array with the cumulative max computed at every element.
Sourcepub fn backward_fill(self, limit: Option<u64>) -> Expr
pub fn backward_fill(self, limit: Option<u64>) -> Expr
Fill missing value with next non-null.
Sourcepub fn forward_fill(self, limit: Option<u64>) -> Expr
pub fn forward_fill(self, limit: Option<u64>) -> Expr
Fill missing value with previous non-null.
Sourcepub fn round(self, decimals: u32) -> Expr
Available on crate feature round_series
only.
pub fn round(self, decimals: u32) -> Expr
round_series
only.Round underlying floating point array to given decimal numbers.
Sourcepub fn round_sig_figs(self, digits: i32) -> Expr
Available on crate feature round_series
only.
pub fn round_sig_figs(self, digits: i32) -> Expr
round_series
only.Round to a number of significant figures.
Sourcepub fn floor(self) -> Expr
Available on crate feature round_series
only.
pub fn floor(self) -> Expr
round_series
only.Floor underlying floating point array to the lowest integers smaller or equal to the float value.
Sourcepub fn ceil(self) -> Expr
Available on crate feature round_series
only.
pub fn ceil(self) -> Expr
round_series
only.Ceil underlying floating point array to the highest integers smaller or equal to the float value.
Sourcepub fn clip(self, min: Expr, max: Expr) -> Expr
Available on crate feature round_series
only.
pub fn clip(self, min: Expr, max: Expr) -> Expr
round_series
only.Clip underlying values to a set boundary.
Sourcepub fn clip_max(self, max: Expr) -> Expr
Available on crate feature round_series
only.
pub fn clip_max(self, max: Expr) -> Expr
round_series
only.Clip underlying values to a set boundary.
Sourcepub fn clip_min(self, min: Expr) -> Expr
Available on crate feature round_series
only.
pub fn clip_min(self, min: Expr) -> Expr
round_series
only.Clip underlying values to a set boundary.
Sourcepub fn abs(self) -> Expr
Available on crate feature abs
only.
pub fn abs(self) -> Expr
abs
only.Convert all values to their absolute/positive value.
Sourcepub fn over<E, IE>(self, partition_by: E) -> Expr
pub fn over<E, IE>(self, partition_by: E) -> Expr
Apply window function over a subgroup. This is similar to a group_by + aggregation + self join. Or similar to window functions in Postgres.
§Example
#[macro_use] extern crate polars_core;
use polars_core::prelude::*;
use polars_lazy::prelude::*;
fn example() -> PolarsResult<()> {
let df = df! {
"groups" => &[1, 1, 2, 2, 1, 2, 3, 3, 1],
"values" => &[1, 2, 3, 4, 5, 6, 7, 8, 8]
}?;
let out = df
.lazy()
.select(&[
col("groups"),
sum("values").over([col("groups")]),
])
.collect()?;
println!("{}", &out);
Ok(())
}
Outputs:
╭────────┬────────╮
│ groups ┆ values │
│ --- ┆ --- │
│ i32 ┆ i32 │
╞════════╪════════╡
│ 1 ┆ 16 │
│ 1 ┆ 16 │
│ 2 ┆ 13 │
│ 2 ┆ 13 │
│ … ┆ … │
│ 1 ┆ 16 │
│ 2 ┆ 13 │
│ 3 ┆ 15 │
│ 3 ┆ 15 │
│ 1 ┆ 16 │
╰────────┴────────╯
pub fn over_with_options<E, IE>( self, partition_by: E, order_by: Option<(E, SortOptions)>, options: WindowMapping, ) -> Expr
pub fn rolling(self, options: RollingGroupOptions) -> Expr
dynamic_group_by
only.pub fn fill_null_with_strategy(self, strategy: FillNullStrategy) -> Expr
Sourcepub fn fill_nan<E>(self, fill_value: E) -> Expr
pub fn fill_nan<E>(self, fill_value: E) -> Expr
Replace the floating point NaN
values by a value.
Sourcepub fn count(self) -> Expr
pub fn count(self) -> Expr
Count the values of the Series or Get counts of the group by operation.
pub fn len(self) -> Expr
Sourcepub fn is_duplicated(self) -> Expr
Available on crate feature is_unique
only.
pub fn is_duplicated(self) -> Expr
is_unique
only.Get a mask of duplicated values.
Sourcepub fn is_unique(self) -> Expr
Available on crate feature is_unique
only.
pub fn is_unique(self) -> Expr
is_unique
only.Get a mask of unique values.
Sourcepub fn approx_n_unique(self) -> Expr
Available on crate feature approx_unique
only.
pub fn approx_n_unique(self) -> Expr
approx_unique
only.Get the approximate count of unique values.
Sourcepub fn logical_or<E>(self, expr: E) -> Expr
pub fn logical_or<E>(self, expr: E) -> Expr
Logical “or” operation.
Sourcepub fn logical_and<E>(self, expr: E) -> Expr
pub fn logical_and<E>(self, expr: E) -> Expr
Logical “and” operation.
Sourcepub fn filter<E>(self, predicate: E) -> Expr
pub fn filter<E>(self, predicate: E) -> Expr
Filter a single column.
Should be used in aggregation context. If you want to filter on a
DataFrame level, use LazyFrame::filter
.
Sourcepub fn is_in<E>(self, other: E) -> Expr
Available on crate feature is_in
only.
pub fn is_in<E>(self, other: E) -> Expr
is_in
only.Check if the values of the left expression are in the lists of the right expr.
Sourcepub fn sort_by<E, IE>(self, by: E, sort_options: SortMultipleOptions) -> Expr
pub fn sort_by<E, IE>(self, by: E, sort_options: SortMultipleOptions) -> Expr
Sort this column by the ordering of another column evaluated from given expr. Can also be used in a group_by context to sort the groups.
§Example
let lf = df! {
"a" => [1, 2, 3, 4, 5],
"b" => [5, 4, 3, 2, 1]
}?.lazy();
let sorted = lf
.select(
vec![col("a").sort_by(col("b"), SortOptions::default())],
)
.collect()?;
assert_eq!(
sorted,
df! { "a" => [5, 4, 3, 2, 1] }?
);
Sourcepub fn repeat_by<E>(self, by: E) -> Expr
Available on crate feature repeat_by
only.
pub fn repeat_by<E>(self, by: E) -> Expr
repeat_by
only.Repeat the column n
times, where n
is determined by the values in by
.
This yields an Expr
of dtype List
.
Sourcepub fn is_first_distinct(self) -> Expr
Available on crate feature is_first_distinct
only.
pub fn is_first_distinct(self) -> Expr
is_first_distinct
only.Get a mask of the first unique value.
Sourcepub fn is_last_distinct(self) -> Expr
Available on crate feature is_last_distinct
only.
pub fn is_last_distinct(self) -> Expr
is_last_distinct
only.Get a mask of the last unique value.
Sourcepub fn mode(self) -> Expr
Available on crate feature mode
only.
pub fn mode(self) -> Expr
mode
only.Compute the mode(s) of this column. This is the most occurring value.
Sourcepub fn exclude(self, columns: impl IntoVec<PlSmallStr>) -> Expr
pub fn exclude(self, columns: impl IntoVec<PlSmallStr>) -> Expr
Exclude a column from a wildcard/regex selection.
You may also use regexes in the exclude as long as they start with ^
and end with $
.
pub fn exclude_dtype<D>(self, dtypes: D) -> Expr
Sourcepub fn interpolate(self, method: InterpolationMethod) -> Expr
Available on crate feature interpolate
only.
pub fn interpolate(self, method: InterpolationMethod) -> Expr
interpolate
only.Fill null values using interpolation.
Sourcepub fn interpolate_by(self, by: Expr) -> Expr
Available on crate feature interpolate_by
only.
pub fn interpolate_by(self, by: Expr) -> Expr
interpolate_by
only.Fill null values using interpolation.
Sourcepub fn rolling_min_by(
self,
by: Expr,
options: RollingOptionsDynamicWindow,
) -> Expr
Available on crate feature rolling_window_by
only.
pub fn rolling_min_by( self, by: Expr, options: RollingOptionsDynamicWindow, ) -> Expr
rolling_window_by
only.Apply a rolling minimum based on another column.
Sourcepub fn rolling_max_by(
self,
by: Expr,
options: RollingOptionsDynamicWindow,
) -> Expr
Available on crate feature rolling_window_by
only.
pub fn rolling_max_by( self, by: Expr, options: RollingOptionsDynamicWindow, ) -> Expr
rolling_window_by
only.Apply a rolling maximum based on another column.
Sourcepub fn rolling_mean_by(
self,
by: Expr,
options: RollingOptionsDynamicWindow,
) -> Expr
Available on crate feature rolling_window_by
only.
pub fn rolling_mean_by( self, by: Expr, options: RollingOptionsDynamicWindow, ) -> Expr
rolling_window_by
only.Apply a rolling mean based on another column.
Sourcepub fn rolling_sum_by(
self,
by: Expr,
options: RollingOptionsDynamicWindow,
) -> Expr
Available on crate feature rolling_window_by
only.
pub fn rolling_sum_by( self, by: Expr, options: RollingOptionsDynamicWindow, ) -> Expr
rolling_window_by
only.Apply a rolling sum based on another column.
Sourcepub fn rolling_quantile_by(
self,
by: Expr,
method: QuantileMethod,
quantile: f64,
options: RollingOptionsDynamicWindow,
) -> Expr
Available on crate feature rolling_window_by
only.
pub fn rolling_quantile_by( self, by: Expr, method: QuantileMethod, quantile: f64, options: RollingOptionsDynamicWindow, ) -> Expr
rolling_window_by
only.Apply a rolling quantile based on another column.
Sourcepub fn rolling_var_by(
self,
by: Expr,
options: RollingOptionsDynamicWindow,
) -> Expr
Available on crate feature rolling_window_by
only.
pub fn rolling_var_by( self, by: Expr, options: RollingOptionsDynamicWindow, ) -> Expr
rolling_window_by
only.Apply a rolling variance based on another column.
Sourcepub fn rolling_std_by(
self,
by: Expr,
options: RollingOptionsDynamicWindow,
) -> Expr
Available on crate feature rolling_window_by
only.
pub fn rolling_std_by( self, by: Expr, options: RollingOptionsDynamicWindow, ) -> Expr
rolling_window_by
only.Apply a rolling std-dev based on another column.
Sourcepub fn rolling_median_by(
self,
by: Expr,
options: RollingOptionsDynamicWindow,
) -> Expr
Available on crate feature rolling_window_by
only.
pub fn rolling_median_by( self, by: Expr, options: RollingOptionsDynamicWindow, ) -> Expr
rolling_window_by
only.Apply a rolling median based on another column.
Sourcepub fn rolling_min(self, options: RollingOptionsFixedWindow) -> Expr
Available on crate feature rolling_window
only.
pub fn rolling_min(self, options: RollingOptionsFixedWindow) -> Expr
rolling_window
only.Apply a rolling minimum.
See: [RollingAgg::rolling_min
]
Sourcepub fn rolling_max(self, options: RollingOptionsFixedWindow) -> Expr
Available on crate feature rolling_window
only.
pub fn rolling_max(self, options: RollingOptionsFixedWindow) -> Expr
rolling_window
only.Apply a rolling maximum.
See: [RollingAgg::rolling_max
]
Sourcepub fn rolling_mean(self, options: RollingOptionsFixedWindow) -> Expr
Available on crate feature rolling_window
only.
pub fn rolling_mean(self, options: RollingOptionsFixedWindow) -> Expr
rolling_window
only.Apply a rolling mean.
See: [RollingAgg::rolling_mean
]
Sourcepub fn rolling_sum(self, options: RollingOptionsFixedWindow) -> Expr
Available on crate feature rolling_window
only.
pub fn rolling_sum(self, options: RollingOptionsFixedWindow) -> Expr
rolling_window
only.Apply a rolling sum.
See: [RollingAgg::rolling_sum
]
Sourcepub fn rolling_median(self, options: RollingOptionsFixedWindow) -> Expr
Available on crate feature rolling_window
only.
pub fn rolling_median(self, options: RollingOptionsFixedWindow) -> Expr
rolling_window
only.Apply a rolling median.
See: [RollingAgg::rolling_median
]
Sourcepub fn rolling_quantile(
self,
method: QuantileMethod,
quantile: f64,
options: RollingOptionsFixedWindow,
) -> Expr
Available on crate feature rolling_window
only.
pub fn rolling_quantile( self, method: QuantileMethod, quantile: f64, options: RollingOptionsFixedWindow, ) -> Expr
rolling_window
only.Apply a rolling quantile.
See: [RollingAgg::rolling_quantile
]
Sourcepub fn rolling_var(self, options: RollingOptionsFixedWindow) -> Expr
Available on crate feature rolling_window
only.
pub fn rolling_var(self, options: RollingOptionsFixedWindow) -> Expr
rolling_window
only.Apply a rolling variance.
Sourcepub fn rolling_std(self, options: RollingOptionsFixedWindow) -> Expr
Available on crate feature rolling_window
only.
pub fn rolling_std(self, options: RollingOptionsFixedWindow) -> Expr
rolling_window
only.Apply a rolling std-dev.
Sourcepub fn rolling_skew(self, window_size: usize, bias: bool) -> Expr
Available on crate features rolling_window
and moment
only.
pub fn rolling_skew(self, window_size: usize, bias: bool) -> Expr
rolling_window
and moment
only.Apply a rolling skew.
Sourcepub fn rolling_map(
self,
f: Arc<dyn Fn(&Series) -> Series + Send + Sync>,
output_type: SpecialEq<Arc<dyn FunctionOutputField>>,
options: RollingOptionsFixedWindow,
) -> Expr
Available on crate feature rolling_window
only.
pub fn rolling_map( self, f: Arc<dyn Fn(&Series) -> Series + Send + Sync>, output_type: SpecialEq<Arc<dyn FunctionOutputField>>, options: RollingOptionsFixedWindow, ) -> Expr
rolling_window
only.Apply a custom function over a rolling/ moving window of the array. This has quite some dynamic dispatch, so prefer rolling_min, max, mean, sum over this.
Sourcepub fn rolling_map_float<F>(self, window_size: usize, f: F) -> Expr
Available on crate feature rolling_window
only.
pub fn rolling_map_float<F>(self, window_size: usize, f: F) -> Expr
rolling_window
only.Apply a custom function over a rolling/ moving window of the array. Prefer this over rolling_apply in case of floating point numbers as this is faster. This has quite some dynamic dispatch, so prefer rolling_min, max, mean, sum over this.
pub fn peak_min(self) -> Expr
peaks
only.pub fn peak_max(self) -> Expr
peaks
only.Sourcepub fn rank(self, options: RankOptions, seed: Option<u64>) -> Expr
Available on crate feature rank
only.
pub fn rank(self, options: RankOptions, seed: Option<u64>) -> Expr
rank
only.Assign ranks to data, dealing with ties appropriately.
Sourcepub fn replace<E>(self, old: E, new: E) -> Expr
Available on crate feature replace
only.
pub fn replace<E>(self, old: E, new: E) -> Expr
replace
only.Replace the given values with other values.
Sourcepub fn replace_strict<E>(
self,
old: E,
new: E,
default: Option<E>,
return_dtype: Option<DataType>,
) -> Expr
Available on crate feature replace
only.
pub fn replace_strict<E>( self, old: E, new: E, default: Option<E>, return_dtype: Option<DataType>, ) -> Expr
replace
only.Replace the given values with other values.
Sourcepub fn cut(
self,
breaks: Vec<f64>,
labels: Option<impl IntoVec<PlSmallStr>>,
left_closed: bool,
include_breaks: bool,
) -> Expr
Available on crate feature cutqcut
only.
pub fn cut( self, breaks: Vec<f64>, labels: Option<impl IntoVec<PlSmallStr>>, left_closed: bool, include_breaks: bool, ) -> Expr
cutqcut
only.Bin continuous values into discrete categories.
Sourcepub fn qcut(
self,
probs: Vec<f64>,
labels: Option<impl IntoVec<PlSmallStr>>,
left_closed: bool,
allow_duplicates: bool,
include_breaks: bool,
) -> Expr
Available on crate feature cutqcut
only.
pub fn qcut( self, probs: Vec<f64>, labels: Option<impl IntoVec<PlSmallStr>>, left_closed: bool, allow_duplicates: bool, include_breaks: bool, ) -> Expr
cutqcut
only.Bin continuous values into discrete categories based on their quantiles.
Sourcepub fn qcut_uniform(
self,
n_bins: usize,
labels: Option<impl IntoVec<PlSmallStr>>,
left_closed: bool,
allow_duplicates: bool,
include_breaks: bool,
) -> Expr
Available on crate feature cutqcut
only.
pub fn qcut_uniform( self, n_bins: usize, labels: Option<impl IntoVec<PlSmallStr>>, left_closed: bool, allow_duplicates: bool, include_breaks: bool, ) -> Expr
cutqcut
only.Bin continuous values into discrete categories using uniform quantile probabilities.
Sourcepub fn rle(self) -> Expr
Available on crate feature rle
only.
pub fn rle(self) -> Expr
rle
only.Get the lengths of runs of identical values.
Sourcepub fn rle_id(self) -> Expr
Available on crate feature rle
only.
pub fn rle_id(self) -> Expr
rle
only.Similar to rle
, but maps values to run IDs.
Sourcepub fn diff(self, n: i64, null_behavior: NullBehavior) -> Expr
Available on crate feature diff
only.
pub fn diff(self, n: i64, null_behavior: NullBehavior) -> Expr
diff
only.Calculate the n-th discrete difference between values.
Sourcepub fn pct_change(self, n: Expr) -> Expr
Available on crate feature pct_change
only.
pub fn pct_change(self, n: Expr) -> Expr
pct_change
only.Computes percentage change between values.
Sourcepub fn skew(self, bias: bool) -> Expr
Available on crate feature moment
only.
pub fn skew(self, bias: bool) -> Expr
moment
only.Compute the sample skewness of a data set.
For normally distributed data, the skewness should be about zero. For
uni-modal continuous distributions, a skewness value greater than zero means
that there is more weight in the right tail of the distribution. The
function skewtest
can be used to determine if the skewness value
is close enough to zero, statistically speaking.
see: scipy
Sourcepub fn kurtosis(self, fisher: bool, bias: bool) -> Expr
Available on crate feature moment
only.
pub fn kurtosis(self, fisher: bool, bias: bool) -> Expr
moment
only.Compute the kurtosis (Fisher or Pearson).
Kurtosis is the fourth central moment divided by the square of the variance. If Fisher’s definition is used, then 3.0 is subtracted from the result to give 0.0 for a normal distribution. If bias is False then the kurtosis is calculated using k statistics to eliminate bias coming from biased moment estimators.
Sourcepub fn upper_bound(self) -> Expr
pub fn upper_bound(self) -> Expr
Get maximal value that could be hold by this dtype.
Sourcepub fn lower_bound(self) -> Expr
pub fn lower_bound(self) -> Expr
Get minimal value that could be hold by this dtype.
pub fn reshape(self, dimensions: &[i64]) -> Expr
dtype-array
only.Sourcepub fn ewm_mean(self, options: EWMOptions) -> Expr
Available on crate feature ewma
only.
pub fn ewm_mean(self, options: EWMOptions) -> Expr
ewma
only.Calculate the exponentially-weighted moving average.
Sourcepub fn ewm_std(self, options: EWMOptions) -> Expr
Available on crate feature ewma
only.
pub fn ewm_std(self, options: EWMOptions) -> Expr
ewma
only.Calculate the exponentially-weighted moving standard deviation.
Sourcepub fn ewm_var(self, options: EWMOptions) -> Expr
Available on crate feature ewma
only.
pub fn ewm_var(self, options: EWMOptions) -> Expr
ewma
only.Calculate the exponentially-weighted moving variance.
Sourcepub fn any(self, ignore_nulls: bool) -> Expr
pub fn any(self, ignore_nulls: bool) -> Expr
Returns whether any of the values in the column are true
.
If ignore_nulls
is False
, Kleene logic is used to deal with nulls:
if the column contains any null values and no true
values, the output
is null.
Sourcepub fn all(self, ignore_nulls: bool) -> Expr
pub fn all(self, ignore_nulls: bool) -> Expr
Returns whether all values in the column are true
.
If ignore_nulls
is False
, Kleene logic is used to deal with nulls:
if the column contains any null values and no true
values, the output
is null.
Sourcepub fn shrink_dtype(self) -> Expr
pub fn shrink_dtype(self) -> Expr
Shrink numeric columns to the minimal required datatype
needed to fit the extrema of this Series
.
This can be used to reduce memory pressure.
Sourcepub fn value_counts(
self,
sort: bool,
parallel: bool,
name: &str,
normalize: bool,
) -> Expr
Available on crate feature dtype-struct
only.
pub fn value_counts( self, sort: bool, parallel: bool, name: &str, normalize: bool, ) -> Expr
dtype-struct
only.Count all unique values and create a struct mapping value to count.
(Note that it is better to turn parallel off in the aggregation context).
The name of the struct field with the counts is given by the parameter name
.
Sourcepub fn unique_counts(self) -> Expr
Available on crate feature unique_counts
only.
pub fn unique_counts(self) -> Expr
unique_counts
only.Returns a count of the unique values in the order of appearance.
This method differs from Expr::value_counts
in that it does not return the
values, only the counts and might be faster.
Sourcepub fn log(self, base: f64) -> Expr
Available on crate feature log
only.
pub fn log(self, base: f64) -> Expr
log
only.Compute the logarithm to a given base.
Sourcepub fn log1p(self) -> Expr
Available on crate feature log
only.
pub fn log1p(self) -> Expr
log
only.Compute the natural logarithm of all elements plus one in the input array.
Sourcepub fn exp(self) -> Expr
Available on crate feature log
only.
pub fn exp(self) -> Expr
log
only.Calculate the exponential of all elements in the input array.
Sourcepub fn entropy(self, base: f64, normalize: bool) -> Expr
Available on crate feature log
only.
pub fn entropy(self, base: f64, normalize: bool) -> Expr
log
only.Compute the entropy as -sum(pk * log(pk)
.
where pk
are discrete probabilities.
Sourcepub fn null_count(self) -> Expr
pub fn null_count(self) -> Expr
Get the null count of the column/group.
Sourcepub fn set_sorted_flag(self, sorted: IsSorted) -> Expr
pub fn set_sorted_flag(self, sorted: IsSorted) -> Expr
Set this Series
as sorted
so that downstream code can use
fast paths for sorted arrays.
§Warning
This can lead to incorrect results if this Series
is not sorted!!
Use with care!
Sourcepub fn hash(self, k0: u64, k1: u64, k2: u64, k3: u64) -> Expr
Available on crate feature row_hash
only.
pub fn hash(self, k0: u64, k1: u64, k2: u64, k3: u64) -> Expr
row_hash
only.Compute the hash of every element.
pub fn to_physical(self) -> Expr
pub fn gather_every(self, n: usize, offset: usize) -> Expr
pub fn extend_constant(self, value: Expr, n: Expr) -> Expr
Sourcepub fn str(self) -> StringNameSpace
Available on crate feature strings
only.
pub fn str(self) -> StringNameSpace
strings
only.Get the string::StringNameSpace
Sourcepub fn binary(self) -> BinaryNameSpace
pub fn binary(self) -> BinaryNameSpace
Get the binary::BinaryNameSpace
Sourcepub fn dt(self) -> DateLikeNameSpace
Available on crate feature temporal
only.
pub fn dt(self) -> DateLikeNameSpace
temporal
only.Get the dt::DateLikeNameSpace
Sourcepub fn list(self) -> ListNameSpace
pub fn list(self) -> ListNameSpace
Get the list::ListNameSpace
Sourcepub fn name(self) -> ExprNameNameSpace
pub fn name(self) -> ExprNameNameSpace
Get the name::ExprNameNameSpace
Sourcepub fn arr(self) -> ArrayNameSpace
Available on crate feature dtype-array
only.
pub fn arr(self) -> ArrayNameSpace
dtype-array
only.Get the array::ArrayNameSpace
.
Sourcepub fn cat(self) -> CategoricalNameSpace
Available on crate feature dtype-categorical
only.
pub fn cat(self) -> CategoricalNameSpace
dtype-categorical
only.Get the CategoricalNameSpace
.
Sourcepub fn struct_(self) -> StructNameSpace
Available on crate feature dtype-struct
only.
pub fn struct_(self) -> StructNameSpace
dtype-struct
only.Get the struct_::StructNameSpace
.
Sourcepub fn meta(self) -> MetaNameSpace
Available on crate feature meta
only.
pub fn meta(self) -> MetaNameSpace
meta
only.Get the meta::MetaNameSpace
Trait Implementations§
Source§impl<'de> Deserialize<'de> for Expr
impl<'de> Deserialize<'de> for Expr
Source§fn deserialize<__D>(
__deserializer: __D,
) -> Result<Expr, <__D as Deserializer<'de>>::Error>where
__D: Deserializer<'de>,
fn deserialize<__D>(
__deserializer: __D,
) -> Result<Expr, <__D as Deserializer<'de>>::Error>where
__D: Deserializer<'de>,
Source§impl ExprEvalExtension for Expr
Available on crate features cumulative_eval
or list_eval
only.
impl ExprEvalExtension for Expr
cumulative_eval
or list_eval
only.Source§impl<'a> IntoIterator for &'a Expr
impl<'a> IntoIterator for &'a Expr
Source§impl Serialize for Expr
impl Serialize for Expr
Source§fn serialize<__S>(
&self,
__serializer: __S,
) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>where
__S: Serializer,
fn serialize<__S>(
&self,
__serializer: __S,
) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>where
__S: Serializer,
Source§impl TreeWalker for Expr
impl TreeWalker for Expr
type Arena = ()
fn apply_children<F>( &self, op: &mut F, arena: &<Expr as TreeWalker>::Arena, ) -> Result<VisitRecursion, PolarsError>
fn map_children<F>( self, f: &mut F, _arena: &mut <Expr as TreeWalker>::Arena, ) -> Result<Expr, PolarsError>
Source§fn visit<V>(
&self,
visitor: &mut V,
arena: &Self::Arena,
) -> Result<VisitRecursion, PolarsError>
fn visit<V>( &self, visitor: &mut V, arena: &Self::Arena, ) -> Result<VisitRecursion, PolarsError>
fn rewrite<R>(
self,
rewriter: &mut R,
arena: &mut Self::Arena,
) -> Result<Self, PolarsError>where
R: RewritingVisitor<Node = Self, Arena = Self::Arena>,
impl Eq for Expr
impl StructuralPartialEq for Expr
Auto Trait Implementations§
impl !Freeze for Expr
impl !RefUnwindSafe for Expr
impl Send for Expr
impl Sync for Expr
impl Unpin for Expr
impl !UnwindSafe for Expr
Blanket Implementations§
Source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
Source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
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T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
Source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
Source§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.Source§impl<Q, K> Equivalent<K> for Q
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Source§impl<T> Instrument for T
impl<T> Instrument for T
Source§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
Source§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
Source§impl<T> IntoEither for T
impl<T> IntoEither for T
Source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left
is true
.
Converts self
into a Right
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otherwise. Read moreSource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
self
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if into_left(&self)
returns true
.
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impl<T> Pointable for T
Source§impl<T> ToCompactString for Twhere
T: Display,
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T: Display,
Source§fn try_to_compact_string(&self) -> Result<CompactString, ToCompactStringError>
fn try_to_compact_string(&self) -> Result<CompactString, ToCompactStringError>
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