daft.functions.strftime#

def strftime(expr: Expression, format: str | None = None) -> Expression:
    """Converts a datetime/date column to a string column.

    Args:
        expr: The datetime or date expression to convert.
        format: The format to use for the conversion. If None, defaults to ISO 8601 format.

    Note:
        The format must be a valid datetime format string. (defaults to ISO 8601 format)
        See: https://docs.rs/chrono/latest/chrono/format/strftime/index.html


    Examples:
        >>> import datetime
        >>> import daft
        >>> from daft.functions import strftime
        >>> df = daft.from_pydict(
        ...     {
        ...         "dates": [datetime.date(2023, 1, 1), datetime.date(2023, 1, 2), datetime.date(2023, 1, 3)],
        ...         "datetimes": [
        ...             datetime.datetime(2023, 1, 1, 12, 1),
        ...             datetime.datetime(2023, 1, 2, 12, 0, 0, 0),
        ...             datetime.datetime(2023, 1, 3, 12, 0, 0, 999_999),
        ...         ],
        ...     }
        ... )
        >>> df = df.with_column("datetimes_s", df["datetimes"].cast(daft.DataType.timestamp("s")))
        >>> df.select(
        ...     strftime(df["dates"]).alias("iso_date"),
        ...     strftime(df["dates"], format="%m/%d/%Y").alias("custom_date"),
        ...     strftime(df["datetimes"]).alias("iso_datetime"),
        ...     strftime(df["datetimes_s"]).alias("iso_datetime_s"),
        ...     strftime(df["datetimes_s"], format="%Y/%m/%d %H:%M:%S").alias("custom_datetime"),
        ... ).show()
        ╭────────────┬─────────────┬────────────────────────────┬─────────────────────┬─────────────────────╮
        │ iso_date   ┆ custom_date ┆ iso_datetime               ┆ iso_datetime_s      ┆ custom_datetime     │
        │ ---        ┆ ---         ┆ ---                        ┆ ---                 ┆ ---                 │
        │ String     ┆ String      ┆ String                     ┆ String              ┆ String              │
        ╞════════════╪═════════════╪════════════════════════════╪═════════════════════╪═════════════════════╡
        │ 2023-01-01 ┆ 01/01/2023  ┆ 2023-01-01T12:01:00        ┆ 2023-01-01T12:01:00 ┆ 2023/01/01 12:01:00 │
        ├╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┤
        │ 2023-01-02 ┆ 01/02/2023  ┆ 2023-01-02T12:00:00        ┆ 2023-01-02T12:00:00 ┆ 2023/01/02 12:00:00 │
        ├╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┤
        │ 2023-01-03 ┆ 01/03/2023  ┆ 2023-01-03T12:00:00.999999 ┆ 2023-01-03T12:00:00 ┆ 2023/01/03 12:00:00 │
        ╰────────────┴─────────────┴────────────────────────────┴─────────────────────┴─────────────────────╯
        <BLANKLINE>
        (Showing first 3 of 3 rows)
    """
    return Expression._call_builtin_scalar_fn("strftime", expr, format)