数据如下:ts_code trade_date open high low close pre_close change pct_chg vol amount 0 600585.SH 20200729 59.60 60.80 59.05 60.68 59.90 0.78 1.3022 319148.23 1923818.3501 600585.SH 20200728 60.18 60.95 59.45 59.90 59.76 0.14 0.2343 284117.71 1711289.7432 600585.SH 20200727 59.62 60.90 59.14 59.76 58.85 0.91 1.5463 362054.35 2171456.7753 600585.SH 20200724 60.46 60.94 58.20 58.85 61.05 -2.20 -3.6036 443699.05 2636469.5884 600585.SH 20200723 60.08 61.50 59.11 61.05 60.97 0.08 0.1312 437532.84 2641867.877.. ... ... ... ... ... ... ... ... ... ... ... 133 600585.SH 20200108 53.00 53.38 52.60 52.69 53.48 -0.79 -1.4772 232324.76 1228341.855134 600585.SH 20200107 53.12 54.13 53.12 53.48 53.32 0.16 0.3001 234783.33 1256641.148135 600585.SH 20200106 54.01 54.54 53.05 53.32 54.68 -1.36 -2.4872 343560.81 1845565.954136 600585.SH 20200103 56.00 56.10 54.44 54.68 55.80 -1.12 -2.0072 288642.12 1585798.292137 600585.SH 20200102 55.30 57.75 55.03 55.80 54.80 1.00 1.8248 411235.67 2306726.977设置 df.sort_index(ascending = True) 或 false 索引 0 都是指向 20200729 这行数据 怎么能把 0 指向 20200102 这行数据呢?