def list_symbols(client, drawing=None, symbol_file=None, sheet=None):
    """List symbols contained on a drawing.

    Args:
        client (obj):
            creopyson Client
        drawing (str, optional):
            Drawing name. Defaults: current active drawing.
        symbol_file (str, optional):
            Symbol file name filter. Defaults: no filter.
        sheet (int, optional):
            Sheet number (0 for all sheets).
            Defaults: The symbol will be added to all sheets.

    Returns:
        (list:dict):
            List of symbols in the drawing.
                id (int): Symbol ID.
                symbol_name (str): Symbol name.
                sheet (int): Sheet number.

    """
    data = {}
    if drawing:
        data["drawing"] = drawing
    if symbol_file:
        data["symbol_file"] = symbol_file
    if sheet:
        data["sheet"] = sheet
    return client._creoson_post("drawing", "list_symbols", data, "symbols")