Apply a function/closure once the logical plan get executed. This function is very similar to [`Expr::apply`], but differs in how it handles aggregat

Assert that the left and right frame are equal. Raises a detailed `AssertionError` if the frames differ. This function is intended for u

Select columns from this DataFrame. Parameters ---------- *exprs Column(s) to select, specified as posit

Assert that the left and right Series are equal. Raises a detailed `AssertionError` if the Series differ. This function is intended for

default branch

Rename the expression. Parameters ---------- name The new name. See Also --------

Execute all the lazy operations and collect them into a [`DataFrame`]. The query is optimized prior to execution. # Example ```rust use polars_core

Push an another [`RowWidths`] into the widths

Convert this Series to a Python list. This operation copies data. Examples -------- >>> s = pl.Series("a",

Start a lazy query from this point. This returns a `LazyFrame` object. Operations on a `LazyFrame` are not executed until this is tr

Add columns to this DataFrame. Added columns will replace existing columns with the same name. Parameters ---------

r""" Cast between data types. Parameters ---------- dtype DataType to cast to. strict

Run any polars aggregation expression against the list' elements. Parameters ---------- expr Expression

Filter the expression based on one or more predicate expressions. The original order of the remaining elements is preserved.

Sort this column. When used in a projection/selection context, the whole column is sorted. When used in a group by context,

Return the number of rows in the context. This is similar to `COUNT(*)` in SQL. Returns ------- Expr Expression of data

Rename Column.

The values of the [`MapScalar`]

Turn a scalar into a column with `length=1`.

Returns the [`DataType`] of the column.

Cast expression to another data type.

Return the data inside this wrapper. # Panics If the `StreamState` was `Waiting`.

Get the single value. This raises an error if there is not exactly one value. Parameters ---------- allow_e

Concat the arrays in a Series dtype List in linear time. Parameters ---------- other Columns to concat i

Return whether all values in the column are `True`. Only works on columns of data type :class:`Boolean`. .. note::

Create a string representation of the query plan. Different optimizations can be turned on or off. Parameters -----

Iterate over [`Series`] as [`AnyValue`]. # Panics This will panic if the array is not rechunked first.

Create a LazyFrame directly from a parquet scan.

Get the [`string::StringNameSpace`]

Get sum value. Notes ----- * Dtypes in {Int8, UInt8, Int16, UInt16} are cast to Int64 before summing to pr

Get the number of schema entries. Examples -------- >>> s = pl.Schema({"x": pl.Int32(), "y": pl.List(pl.String)})

Convert from Date/Time/Datetime into String with the given format. See [chrono strftime/strptime](https://docs.rs/chrono/0.4.19/chrono/format/strftime

Get an ordered mapping of column names to their data type. This is an alias for the :attr:`schema` property. See Also

Select all list columns. .. warning:: This functionality is considered **unstable**. It may be changed at any point without

Get a slice of this expression. Parameters ---------- offset Start index. Negative indexing is supported

Join all string items in a sublist and place a separator between them. This errors if inner type of list `!= String`. Param

Check if the list array contain an element

Select columns from this LazyFrame. Parameters ---------- *exprs Column(s) to select, specified as posit

Returns an iterator of `Option<&T>` over every element of this array.

Write to Apache Parquet file. Parameters ---------- file File path or writable file-like object to which

Start a group by operation. Parameters ---------- *by Column(s) to group by. Accepts expression input. S

Compute expressions over the given groups. This expression is similar to performing a group by aggregation and joining the r

Finish builder