DataFrame 切片数据提取

Vars DataFrame df;Events OnInit() { Array<Array<Numeric>> datas=[[0.11,0.12,0.13,0.14,0.15],[0.21,0.22,0.23,0.24,0.25],[0.31,0.32,0.33,0.34,0.35],[0.41,0.42,0.43,0.44,0.45]]; Array<String> columns = ["北京","天津","上海","沈阳","广州"]; df.init(datas,columns); //2. pd.iloc,通过行数和列数取结果 tmp_df = df.iloc([1:3],[:]); // 第1-2行 Numeric i = 1; Numeric j = 3; ******* tmp_df1 = df.iloc([i:j],[:]); // 第1-2行 }在上文打星号的最后一句，以变量i,j 去切片dataframe，碰到错误C2398. 如果要用变量来数据切片，应该怎样写？