Expression

Command	Description
polars arg-where	Creates an expression that returns the arguments where expression is true.
polars as	Creates an alias expression.
polars col	Creates a named column expression.
polars concat-str	Creates a concat string expression.
polars datepart	Creates an expression for capturing the specified datepart in a column.
polars horizontal	Horizontal calculation across multiple columns.
polars is-in	Creates an is-in expression or checks to see if the elements are contained in the right series
polars lit	Creates a literal expression.
polars otherwise	Completes a when expression.
polars replace	Create an expression that replaces old values with new values
polars selector	Create column selectors for use in polars commands.
polars selector all	Creates a selector that selects all columns.
polars selector alpha	Select all columns with alphabetic names (eg: only letters). Matching column names cannot contain any non-alphabetic characters. Note that the definition of "alphabetic" consists of all valid Unicode alphabetic characters by default; this can be changed by setting `--ascii-only`.
polars selector alphanumeric	Select all columns with alphanumeric names (eg: only letters). Matching column names cannot contain any non-alphanumeric characters. Note that the definition of "alphanumeric" consists of all valid Unicode alphanumeric characters by default; this can be changed by setting `ascii_only=true`.
polars selector array	Select all array columns. Optionally filter by fixed width.
polars selector binary	Select all binary columns.
polars selector boolean	Select all boolean columns.
polars selector by-dtype	Creates a selector that selects columns by data type.
polars selector by-index	Select columns by their index position. Supports negative indices (e.g., -1 for the last column).
polars selector by-name	Creates a selector that selects columns by name.
polars selector categorical	Select all categorical columns.
polars selector contains	Select columns whose names contain the given literal substring(s).
polars selector date	Select all date columns.
polars selector datetime	Select all datetime columns. Optionally filter by time unit (ns, us, ms) and/or timezone.
polars selector decimal	Select all decimal columns.
polars selector digit	Select columns whose names consist entirely of digit characters. By default uses Unicode decimal digits; use `--ascii-only` to restrict to ASCII 0-9.
polars selector duration	Select all duration columns. Optionally filter by time unit (ns, us, ms).
polars selector empty	Create an empty selector that matches no columns. Useful as a base for selector composition.
polars selector ends-with	Select columns that end with the given substring(s).
polars selector enum	Select all enum columns.
polars selector exclude	Select all columns except those with the given name(s). This is the inverse of `polars selector by-name`.
polars selector first	Creates a selector that selects the first column(s) by index.
polars selector float	Select all float columns.
polars selector integer	Select all integer columns.
polars selector last	Creates a selector that selects the last column(s) by index.
polars selector list	Select all list columns.
polars selector matches	Select all columns that match the given regex pattern.
polars selector nested	Select all nested columns (list, array, or struct).
polars selector not	Inverts selector.
polars selector numeric	Select all numeric columns.
polars selector object	Select all object columns.
polars selector signed-integer	Select all signed integer columns.
polars selector starts-with	Select columns that start with the given substring(s).
polars selector string	Select all string columns. Use `--include-categorical` to also select categorical columns.
polars selector struct	Select all struct columns.
polars selector temporal	Select all temporal columns (date, datetime, duration, and time).
polars selector unsigned-integer	Select all unsigned integer columns.
polars truncate	Divide the date/datetime range into buckets.
polars when	Creates and modifies a when expression.