import re


def get_voltage_start_step( content ):
    """
    Gets the voltage start point and step used during the sweep

    :param content: The content to search
    :returns: A tuple of floats ( start, step )
    """
    volt_search = ' SetScale/P x (.*?),(.*?),"V"'
    match = re.search( volt_search, content, flags = re.IGNORECASE )

    if match is None:
        # no match found, raise exception
        raise RuntimeError( 'Voltage start, step not found' )

    # match found
    if match.group( 1 ) is None:
        # voltage start not found
        raise RuntimeError( 'Voltage start not found' )

    if match.group( 2 ) is None:
        # voltage step not found
        raise RuntimeError( 'Voltage step not found' )

    return ( float( match.group( 1 ) ), float( match.group( 2 ) ) )