给出一个带有日期时间索引的数据框：
df =
FB GOOGL HD JNJ KO MCD MSFT
Date
2007-02-23 0.0000 235.49821 40.98 64.16 23.6350 46.050 28.90
2007-03-02 0.0000 219.55276 38.98 61.84 22.9250 43.630 27.76
2007-03-09 0.0000 226.65464 38.65 62.14 23.7850 44.160 27.29
2007-03-16 0.0000 220.37356 37.50 60.51 23.5900 43.460 27.31
2007-03-23 0.0000 231.12898 38.23 60.50 24.0300 45.050 27.99
2007-03-30 0.0000 229.16207 36.74 60.25 24.0000 45.030 27.87
2007-04-06 0.0000 235.97868 38.02 61.56 24.7550 45.770 28.55
2007-04-13 0.0000 233.37616 37.89 62.35 24.9450 47.680 28.62
2007-04-20 0.0000 241.47901 39.24 65.08 26.0650 48.350 29.02
2007-04-27 0.0000 239.73732 38.46 64.16 26.0350 48.960 30.13
2007-05-04 0.0000 235.78349 38.92 64.47 26.6250 49.920 30.56
2007-05-11 0.0000 233.60138 38.91 62.26 26.3600 50.700 30.90
2007-05-18 0.0000 235.37309 38.87 63.42 26.3050 52.330 30.83
2007-05-25 0.0000 241.88941 38.37 63.23 25.9450 50.860 30.48
2007-06-01 15.000 250.46772 39.22 63.38 26.3900 50.910 30.60
2007-06-08 20.000 257.94997 37.94 62.13 25.8300 51.380 30.05
2007-06-15 25.000 253.19536 38.00 62.76 25.7900 52.190 30.49
2007-06-22 30.000 262.69957 39.53 61.11 25.8250 50.420 29.50
2007-06-29 35.000 261.93383 39.35 61.62 26.1500 50.760 29.47
我有一个需要进行公式计算的日期列表。但是，由于某些特定的错误，当股票进入数据框/市场时，我的代码完全中断了（0表示此时股票没有价值）。
假设我需要进行计算的日期列表是
myList = ["2007-06-01"]
我希望有一个更新的数据框，如果索引的日期与myList日期匹配，并且该列的该日期之前的值为0，则将该0用作下一列的值如下图所示。
dfUpdated =
FB GOOGL HD JNJ KO MCD MSFT
Date
2007-02-23 0.0000 235.49821 40.98 64.16 23.6350 46.050 28.90
2007-03-02 0.0000 219.55276 38.98 61.84 22.9250 43.630 27.76
2007-03-09 0.0000 226.65464 38.65 62.14 23.7850 44.160 27.29
2007-03-16 0.0000 220.37356 37.50 60.51 23.5900 43.460 27.31
2007-03-23 0.0000 231.12898 38.23 60.50 24.0300 45.050 27.99
2007-03-30 0.0000 229.16207 36.74 60.25 24.0000 45.030 27.87
2007-04-06 0.0000 235.97868 38.02 61.56 24.7550 45.770 28.55
2007-04-13 0.0000 233.37616 37.89 62.35 24.9450 47.680 28.62
2007-04-20 0.0000 241.47901 39.24 65.08 26.0650 48.350 29.02
2007-04-27 0.0000 239.73732 38.46 64.16 26.0350 48.960 30.13
2007-05-04 0.0000 235.78349 38.92 64.47 26.6250 49.920 30.56
2007-05-11 0.0000 233.60138 38.91 62.26 26.3600 50.700 30.90
2007-05-18 0.0000 235.37309 38.87 63.42 26.3050 52.330 30.83
2007-05-25 15.000 241.88941 38.37 63.23 25.9450 50.860 30.48
2007-06-01 15.000 250.46772 39.22 63.38 26.3900 50.910 30.60
2007-06-08 20.000 257.94997 37.94 62.13 25.8300 51.380 30.05
2007-06-15 25.000 253.19536 38.00 62.76 25.7900 52.190 30.49
2007-06-22 30.000 262.69957 39.53 61.11 25.8250 50.420 29.50
2007-06-29 35.000 261.93383 39.35 61.62 26.1500 50.760 29.47
因此，由于这两个条件，从2007年5月25日开始，FB股票从0.000变为15.000。
答案 0 :(得分：2)
使用get_loc
df.iloc[df.index.get_loc("2007-06-01")-1,0]=df.iloc[df.index.get_loc("2007-06-01"),0]
df
Out[531]:
FB GOOGL HD JNJ KO MCD MSFT
Date
2007-02-23 0.0 235.49821 40.98 64.16 23.635 46.05 28.90
2007-03-02 0.0 219.55276 38.98 61.84 22.925 43.63 27.76
2007-03-09 0.0 226.65464 38.65 62.14 23.785 44.16 27.29
2007-03-16 0.0 220.37356 37.50 60.51 23.590 43.46 27.31
2007-03-23 0.0 231.12898 38.23 60.50 24.030 45.05 27.99
2007-03-30 0.0 229.16207 36.74 60.25 24.000 45.03 27.87
2007-04-06 0.0 235.97868 38.02 61.56 24.755 45.77 28.55
2007-04-13 0.0 233.37616 37.89 62.35 24.945 47.68 28.62
2007-04-20 0.0 241.47901 39.24 65.08 26.065 48.35 29.02
2007-04-27 0.0 239.73732 38.46 64.16 26.035 48.96 30.13
2007-05-04 0.0 235.78349 38.92 64.47 26.625 49.92 30.56
2007-05-11 0.0 233.60138 38.91 62.26 26.360 50.70 30.90
2007-05-18 0.0 235.37309 38.87 63.42 26.305 52.33 30.83
2007-05-25 15.0 241.88941 38.37 63.23 25.945 50.86 30.48
2007-06-01 15.0 250.46772 39.22 63.38 26.390 50.91 30.60
2007-06-08 20.0 257.94997 37.94 62.13 25.830 51.38 30.05
2007-06-15 25.0 253.19536 38.00 62.76 25.790 52.19 30.49
2007-06-22 30.0 262.69957 39.53 61.11 25.825 50.42 29.50
2007-06-29 35.0 261.93383 39.35 61.62 26.150 50.76 29.47