def decimal(
    size: int,
    *,
    precision: Optional[int] = 1,
    separator: Optional[str] = " ",
) -> str:
    """Convert a filesize in to a string (powers of 1000, SI prefixes).

    In this convention, ``1000 B = 1 kB``.

    This is typically the format used to advertise the storage
    capacity of USB flash drives and the like (*256 MB* meaning
    actually a storage capacity of more than *256 000 000 B*),
    or used by **Mac OS X** since v10.6 to report file sizes.

    Arguments:
        int (size): A file size.
        int (precision): The number of decimal places to include (default = 1).
        str (separator): The string to separate the value from the units (default = " ").

    Returns:
        `str`: A string containing a abbreviated file size and units.

    Example:
        >>> filesize.decimal(30000)
        '30.0 kB'
        >>> filesize.decimal(30000, precision=2, separator="")
        '30.00kB'

    """
    return _to_str(
        size,
        ("kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"),
        1000,
        precision=precision,
        separator=separator,
    )
Convert a filesize in to a string (powers of 1000, SI prefixes).

    In this convention, ``1000 B = 1 kB``.

    This is typically the format used to advertise the storage
    capacity of USB flash drives and the like (*256 MB* meaning
    actually a storage capacity of more than *256 000 000 B*),
    or used by **Mac OS X** since v10.6 to report file sizes.

    Arguments:
        int (size): A file size.
        int (precision): The number of decimal places to include (default = 1).
        str (separator): The string to separate the value from the units (default = " ").

    Returns:
        `str`: A string containing a abbreviated file size and units.

    Example:
        >>> filesize.decimal(30000)
        '30.0 kB'
        >>> filesize.decimal(30000, precision=2, separator="")
        '30.00kB'

    
rich/filesize.py