pub fn left_join<I, S>(&self, other: &DataFrame, left_on: I, right_on: I) -> Result<DataFrame>
    where
        I: IntoIterator<Item = S>,
        S: AsRef<str>,
    {
        self.join(other, left_on, right_on, JoinType::Left, None)
    }
/// Perform a left join on two DataFrames
/// # Example
///
/// ```no_run
/// # use polars_core::prelude::*;
/// 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);
/// # Ok::<(), PolarsError>(())
/// ```
///
/// Output:
///
/// ```text
/// shape: (5, 2)
/// +-----------------+--------+
/// | Wavelength (nm) | Color  |
/// | ---             | ---    |
/// | f64             | str    |
/// +=================+========+
/// | 480             | Blue   |
/// +-----------------+--------+
/// | 650             | Red    |
/// +-----------------+--------+
/// | 577             | Yellow |
/// +-----------------+--------+
/// | 1201            | null   |
/// +-----------------+--------+
/// | 100             | null   |
/// +-----------------+--------+
/// ```
Perform a left join on two DataFrames
Perform a left join on two DataFrames
pub fn left_join<I, S>(&self, other: &DataFrame, left_on: I, right_on: I) -> Result<DataFrame>
    where
        I: IntoIterator<Item = S>,
        S: AsRef<str>,
    {
        self.join(other, left_on, right_on, JoinType::Left, None)
    }
pub fn left_join < I , S > ( & self , other : & DataFrame , left_on : I , right_on : I ) -> Result < DataFrame > where I : IntoIterator < Item = S > , S : AsRef < str > , { self . join ( other , left_on , right_on , JoinType :: Left , None ) }
Perform a left join on two DataFrames
Perform a left join on two DataFrames
&self
other
&DataFrame
left_on
I
right_on
I
&self
other
&DataFrame
left_on
I
right_on
I
example
None
use polars_core::prelude::*;
None
ok::<(), polarserror>(())
None