python 将前一行的值与当前行的值进行比较
python comparing values of previous rows with current row
我有这样一个数据框：
| | Date | Open | High | Low | Close_DAILY | SMA200 | 4H | 1H | BUY |
|-----+---------------------+---------+---------+---------+---------------+----------+---------+---------+-------|
| 0 | 2021-02-26 00:00:00 | 234.761 | 239.4 | 209.105 | 221.717 | nan | 247.751 | 253.4 | nan |
| 1 | 2021-02-27 00:00:00 | 221.959 | 237.77 | 219.011 | 225.385 | nan | 247.886 | 251.655 | nan |
| 2 | 2021-02-28 00:00:00 | 225.457 | 229.4 | 195 | 210.214 | nan | 254.707 | 244.716 | nan |
| 3 | 2021-03-01 00:00:00 | 210.118 | 260 | 209.12 | 254.964 | nan | 246.808 | 250.706 | nan |
| 4 | 2021-03-02 00:00:00 | 254.949 | 264.9 | 227 | 239.684 | nan | 234.915 | 248.799 | nan |
| 5 | 2021-03-03 00:00:00 | 239.72 | 254.848 | 236.002 | 240.57 | nan | 228.379 | 247.751 | nan |
| 6 | 2021-03-04 00:00:00 | 240.48 | 249.988 | 225.531 | 229.637 | nan | 215.144 | 241.73 | nan |
....
| 214 | 2021-09-28 00:00:00 | 335.5 | 344.6 | 330 | 333 | 395.051 | 334.799 | 226.795 | nan |
| 215 | 2021-09-29 00:00:00 | 332.9 | 375.4 | 331.2 | 367.7 | 395.508 | 343.926 | 225.282 | nan |
| 216 | 2021-09-30 00:00:00 | 367.7 | 388.8 | 366.4 | 387.5 | 396.13 | 351.528 | 225.025 | nan |
| 217 | 2021-10-01 00:00:00 | 387.5 | 423.4 | 381.5 | 421.5 | 396.965 | 346.839 | 223.853 | nan |
| 218 | 2021-10-02 00:00:00 | 421.4 | 438.2 | 410.6 | 427.1 | 397.807 | 346.885 | 227.023 | nan |
| 219 | 2021-10-03 00:00:00 | 427 | 437.2 | 421.5 | 430.5 | 398.611 | 337.361 | 228.571 | nan |
| 220 | 2021-10-04 00:00:00 | 430.5 | 430.9 | 410.9 | 426.3 | 399.435 | 338.293 | 228.754 | nan |
| 221 | 2021-10-05 00:00:00 | 426.4 | 444 | 424 | 442.1 | 400.331 | 339.057 | 229.552 | nan |
| 222 | 2021-10-06 00:00:00 | 442 | 442.8 | 414.7 | 434.9 | 401.184 | 342.6 | 225.848 | nan |
| 223 | 2021-10-07 00:00:00 | 434.9 | 450 | 423.6 | 438.5 | 402.053 | 346 | 224.936 | YESSS |
在“买入”列中，如果该行的收盘价低于 7 天前的低点并且 Close_DAILY 高于 SMA200，我想得到一个 yesss。我正在使用下面的代码，但正如您在数据框的最后一行中看到的那样，它返回了一个 YESSS，尽管 7 天前的低点高于那几天的收盘价。
daily.loc[(daily['Low'].shift(-7)>daily['Close_DAILY']) & (daily['Close_DAILY']>daily['SMA200']), 'BUY']='YESSS'
基本上，如果 Close_DAILY 低于 7 天前的低点，我想做的是在买入栏中获得 YESSS。
要获得前 7 天的最低值，您应该使用 daily['Low'].shift(7)。
请查看 pandas 文档了解更多详情：https://pandas.pydata.org/docs/reference/api/pandas.DataFrame.shift.html
我有这样一个数据框：
| | Date | Open | High | Low | Close_DAILY | SMA200 | 4H | 1H | BUY |
|-----+---------------------+---------+---------+---------+---------------+----------+---------+---------+-------|
| 0 | 2021-02-26 00:00:00 | 234.761 | 239.4 | 209.105 | 221.717 | nan | 247.751 | 253.4 | nan |
| 1 | 2021-02-27 00:00:00 | 221.959 | 237.77 | 219.011 | 225.385 | nan | 247.886 | 251.655 | nan |
| 2 | 2021-02-28 00:00:00 | 225.457 | 229.4 | 195 | 210.214 | nan | 254.707 | 244.716 | nan |
| 3 | 2021-03-01 00:00:00 | 210.118 | 260 | 209.12 | 254.964 | nan | 246.808 | 250.706 | nan |
| 4 | 2021-03-02 00:00:00 | 254.949 | 264.9 | 227 | 239.684 | nan | 234.915 | 248.799 | nan |
| 5 | 2021-03-03 00:00:00 | 239.72 | 254.848 | 236.002 | 240.57 | nan | 228.379 | 247.751 | nan |
| 6 | 2021-03-04 00:00:00 | 240.48 | 249.988 | 225.531 | 229.637 | nan | 215.144 | 241.73 | nan |
....
| 214 | 2021-09-28 00:00:00 | 335.5 | 344.6 | 330 | 333 | 395.051 | 334.799 | 226.795 | nan |
| 215 | 2021-09-29 00:00:00 | 332.9 | 375.4 | 331.2 | 367.7 | 395.508 | 343.926 | 225.282 | nan |
| 216 | 2021-09-30 00:00:00 | 367.7 | 388.8 | 366.4 | 387.5 | 396.13 | 351.528 | 225.025 | nan |
| 217 | 2021-10-01 00:00:00 | 387.5 | 423.4 | 381.5 | 421.5 | 396.965 | 346.839 | 223.853 | nan |
| 218 | 2021-10-02 00:00:00 | 421.4 | 438.2 | 410.6 | 427.1 | 397.807 | 346.885 | 227.023 | nan |
| 219 | 2021-10-03 00:00:00 | 427 | 437.2 | 421.5 | 430.5 | 398.611 | 337.361 | 228.571 | nan |
| 220 | 2021-10-04 00:00:00 | 430.5 | 430.9 | 410.9 | 426.3 | 399.435 | 338.293 | 228.754 | nan |
| 221 | 2021-10-05 00:00:00 | 426.4 | 444 | 424 | 442.1 | 400.331 | 339.057 | 229.552 | nan |
| 222 | 2021-10-06 00:00:00 | 442 | 442.8 | 414.7 | 434.9 | 401.184 | 342.6 | 225.848 | nan |
| 223 | 2021-10-07 00:00:00 | 434.9 | 450 | 423.6 | 438.5 | 402.053 | 346 | 224.936 | YESSS |
在“买入”列中，如果该行的收盘价低于 7 天前的低点并且 Close_DAILY 高于 SMA200，我想得到一个 yesss。我正在使用下面的代码，但正如您在数据框的最后一行中看到的那样，它返回了一个 YESSS，尽管 7 天前的低点高于那几天的收盘价。
daily.loc[(daily['Low'].shift(-7)>daily['Close_DAILY']) & (daily['Close_DAILY']>daily['SMA200']), 'BUY']='YESSS'
基本上，如果 Close_DAILY 低于 7 天前的低点，我想做的是在买入栏中获得 YESSS。
要获得前 7 天的最低值，您应该使用 daily['Low'].shift(7)。
请查看 pandas 文档了解更多详情：https://pandas.pydata.org/docs/reference/api/pandas.DataFrame.shift.html