def select()

in python/datafusion/dataframe.py [0:0]

• 5 lines of code
• 3 McCabe index (conditional complexity)

    def select(self, *exprs: Expr | str) -> DataFrame:
        """Project arbitrary expressions into a new :py:class:`DataFrame`.

        Args:
            exprs: Either column names or :py:class:`~datafusion.expr.Expr` to select.

        Returns:
            DataFrame after projection. It has one column for each expression.

        Example usage:

        The following example will return 3 columns from the original dataframe.
        The first two columns will be the original column ``a`` and ``b`` since the
        string "a" is assumed to refer to column selection. Also a duplicate of
        column ``a`` will be returned with the column name ``alternate_a``::

            df = df.select("a", col("b"), col("a").alias("alternate_a"))

        """
        exprs_internal = [
            Expr.column(arg).expr if isinstance(arg, str) else arg.expr for arg in exprs
        ]
        return DataFrame(self.df.select(*exprs_internal))