Trait DataFrameJoinOps

pub trait DataFrameJoinOps: IntoDf {
    // Provided methods
    fn join(
        &self,
        other: &DataFrame,
        left_on: impl IntoIterator<Item = impl Into<PlSmallStr>>,
        right_on: impl IntoIterator<Item = impl Into<PlSmallStr>>,
        args: JoinArgs,
    ) -> Result<DataFrame, PolarsError> { ... }
    fn inner_join(
        &self,
        other: &DataFrame,
        left_on: impl IntoIterator<Item = impl Into<PlSmallStr>>,
        right_on: impl IntoIterator<Item = impl Into<PlSmallStr>>,
    ) -> Result<DataFrame, PolarsError> { ... }
    fn left_join(
        &self,
        other: &DataFrame,
        left_on: impl IntoIterator<Item = impl Into<PlSmallStr>>,
        right_on: impl IntoIterator<Item = impl Into<PlSmallStr>>,
    ) -> Result<DataFrame, PolarsError> { ... }
    fn full_join(
        &self,
        other: &DataFrame,
        left_on: impl IntoIterator<Item = impl Into<PlSmallStr>>,
        right_on: impl IntoIterator<Item = impl Into<PlSmallStr>>,
    ) -> Result<DataFrame, PolarsError> { ... }
}

Available on crate feature polars-ops only.

Provided Methods

fn join( &self, other: &DataFrame, left_on: impl IntoIterator<Item = impl Into<PlSmallStr>>, right_on: impl IntoIterator<Item = impl Into<PlSmallStr>>, args: JoinArgs, ) -> Result<DataFrame, PolarsError>

Generic join method. Can be used to join on multiple columns.

Example

let df1: DataFrame = df!("Fruit" => &["Apple", "Banana", "Pear"],
                         "Phosphorus (mg/100g)" => &[11, 22, 12])?;
let df2: DataFrame = df!("Name" => &["Apple", "Banana", "Pear"],
                         "Potassium (mg/100g)" => &[107, 358, 115])?;

let df3: DataFrame = df1.join(&df2, ["Fruit"], ["Name"], JoinArgs::new(JoinType::Inner))?;
assert_eq!(df3.shape(), (3, 3));
println!("{}", df3);

Output:

shape: (3, 3)
+--------+----------------------+---------------------+
| Fruit  | Phosphorus (mg/100g) | Potassium (mg/100g) |
| ---    | ---                  | ---                 |
| str    | i32                  | i32                 |
+========+======================+=====================+
| Apple  | 11                   | 107                 |
+--------+----------------------+---------------------+
| Banana | 22                   | 358                 |
+--------+----------------------+---------------------+
| Pear   | 12                   | 115                 |
+--------+----------------------+---------------------+

fn inner_join( &self, other: &DataFrame, left_on: impl IntoIterator<Item = impl Into<PlSmallStr>>, right_on: impl IntoIterator<Item = impl Into<PlSmallStr>>, ) -> Result<DataFrame, PolarsError>

Perform an inner join on two DataFrames.

Example

fn join_dfs(left: &DataFrame, right: &DataFrame) -> PolarsResult<DataFrame> {
    left.inner_join(right, ["join_column_left"], ["join_column_right"])
}

fn left_join( &self, other: &DataFrame, left_on: impl IntoIterator<Item = impl Into<PlSmallStr>>, right_on: impl IntoIterator<Item = impl Into<PlSmallStr>>, ) -> Result<DataFrame, PolarsError>

Perform a left outer join on two DataFrames

Example

let df1: DataFrame = df!("Wavelength (nm)" => &[480.0, 650.0, 577.0, 1201.0, 100.0])?;
let df2: DataFrame = df!("Color" => &["Blue", "Yellow", "Red"],
                         "Wavelength nm" => &[480.0, 577.0, 650.0])?;

let df3: DataFrame = df1.left_join(&df2, ["Wavelength (nm)"], ["Wavelength nm"])?;
println!("{:?}", df3);

Output:

shape: (5, 2)
+-----------------+--------+
| Wavelength (nm) | Color  |
| ---             | ---    |
| f64             | str    |
+=================+========+
| 480             | Blue   |
+-----------------+--------+
| 650             | Red    |
+-----------------+--------+
| 577             | Yellow |
+-----------------+--------+
| 1201            | null   |
+-----------------+--------+
| 100             | null   |
+-----------------+--------+

fn full_join( &self, other: &DataFrame, left_on: impl IntoIterator<Item = impl Into<PlSmallStr>>, right_on: impl IntoIterator<Item = impl Into<PlSmallStr>>, ) -> Result<DataFrame, PolarsError>

Perform a full outer join on two DataFrames

Example

fn join_dfs(left: &DataFrame, right: &DataFrame) -> PolarsResult<DataFrame> {
    left.full_join(right, ["join_column_left"], ["join_column_right"])
}

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl DataFrameJoinOps for DataFrame