小编Geo*_*nty的帖子

我有一个像这样的pandas数据框:

                     AAPL   IBM  GOOG  XOM
2011-01-10 16:00:00  1500     0     0    0
2011-01-11 16:00:00     0     0     0    0
2011-01-12 16:00:00     0     0     0    0
2011-01-13 16:00:00 -1500  4000     0    0
2011-01-14 16:00:00     0     0     0    0
2011-01-18 16:00:00     0     0     0    0

我的目标是通过添加前面的行值来填充行.结果如下所示:

                     AAPL   IBM  GOOG  XOM
2011-01-10 16:00:00  1500     0     0    0
2011-01-11 16:00:00  1500     0     0    0
2011-01-12 16:00:00  1500     0     0    0
2011-01-13 16:00:00     0  4000     0    0
2011-01-14 16:00:00     0  4000     0    0
2011-01-18 16:00:00     0  4000 …