List

The following methods are available under the expr.list attribute.

Expr.list.__getitem__(item)	Get the value by index in the sublists.
Expr.list.agg(expr)	Run any polars aggregation expression against the lists' elements.
Expr.list.all(*[, ignore_nulls])	Evaluate whether all boolean values in a list are true.
Expr.list.any(*[, ignore_nulls])	Evaluate whether any boolean value in a list is true.
Expr.list.arg_max()	Retrieve the index of the maximum value in every sub-list.
Expr.list.arg_min()	Retrieve an index of a minimal value in every sublist.
Expr.list.concat(other)	Concat the arrays in a Series dtype List in linear time.
Expr.list.contains(item, *[, nulls_equal])	Check if sub-lists contain the given item.
Expr.list.count_matches(element)	Count how often the value produced by element occurs.
Expr.list.diff([n, null_behavior])	Calculate the first discrete difference between shifted items of every sub-list.
Expr.list.drop_nulls()	Drop all null values in the list.
Expr.list.eval(expr, *[, parallel])	Run any polars expression against every lists' elements.
Expr.list.explode(*[, empty_as_null, keep_nulls])	Returns a column with a separate row for every sub-list.
Expr.list.filter(predicate)	Filter elements in each list by a boolean expression.
Expr.list.first()	Get the first value of every sub-list.
Expr.list.gather(indices, *[, null_on_oob])	Take sub-lists by multiple indices.
Expr.list.gather_every(n[, offset])	Take every n-th value start from offset in every sub-list.
Expr.list.get(index, *[, null_on_oob])	Get the value by index in every sublist.
Expr.list.head([n])	Slice the first n values of every sub-list.
Expr.list.item(*[, allow_empty])	Get the single value of the sub-list.
Expr.list.join(separator, *[, ignore_nulls])	Join all string items in a sub-list and place a separator between them.
Expr.list.last()	Get the last value of every sub-list.
Expr.list.len()	Return the number of elements in each list.
Expr.list.max()	Compute the max value of the lists in the array.
Expr.list.mean()	Compute the mean value of the lists in the array.
Expr.list.median()	Compute the median value of the lists in the array.
Expr.list.min()	Compute the min value of the lists in the array.
Expr.list.n_unique()	Count the number of unique values in every sub-list.
Expr.list.reverse()	Reverse the arrays in the list.
Expr.list.sample([n, fraction, ...])	Sample from this list.
Expr.list.set_difference(other)	Compute the SET DIFFERENCE between the elements in this list and the elements of other.
Expr.list.set_intersection(other)	Compute the SET INTERSECTION between the elements in this list and the elements of other.
Expr.list.set_symmetric_difference(other)	Compute the SET SYMMETRIC DIFFERENCE between the elements in this list and the elements of other.
Expr.list.set_union(other)	Compute the SET UNION between the elements in this list and the elements of other.
Expr.list.shift([n])	Shift every sub-lists values by the given number of indices.
Expr.list.slice(offset[, length])	Slice every sub-list.
Expr.list.sort(*[, descending, nulls_last])	Sort the lists in this column.
Expr.list.std([ddof])	Compute the std value of the lists in the array.
Expr.list.sum()	Sum all the lists in the array.
Expr.list.tail([n])	Slice the last n values of every sub-list.
Expr.list.to_array(width)	Convert a List column into an Array column with the same inner data type.
Expr.list.to_struct([n_field_strategy, ...])	Convert the Series of type List to a Series of type Struct.
Expr.list.unique(*[, maintain_order])	Get the unique/distinct values in every sub-list.
Expr.list.var([ddof])	Compute the var value of the lists in the array.