Module `Agg.String`

val min : t -> string -> string option

min df name is the lexicographically smallest non-null string, or None if the column is empty or all null.

val max : t -> string -> string option

max df name is the lexicographically largest non-null string, or None if the column is empty or all null.

val concat : t -> string -> ?sep:string -> unit -> string

concat df name ?sep () is the concatenation of all non-null strings. sep defaults to "". Empty string if all values are null.

val unique : t -> string -> string array

unique df name is the array of unique non-null values.

Order is not guaranteed.

val nunique : t -> string -> int

nunique df name is the number of unique non-null values.

val mode : t -> string -> string option

mode df name is the most frequent non-null value, or None if the column is empty or all null.