我尝试在条件下替换特定行的值
以下是示例 Dataframe ：

import pandas as pd

# create a Series with the given data
s = pd.Series([1, -1, 0, 0, 0, 1, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, -1, 1, 0, -1, 0, 0, 1, 0, 0, -1, 1, -1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, -1, 1, -1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, -1, 0, 0, 0, 0], name='position_short')

# create a dataframe with the Series as the only column
df = pd.DataFrame(s)

# set the index of the dataframe to the bar numbers
df.index = range(7, 108)

它看起来像这样：

Bar numbers
7      1
8     -1
9      0
10     0
11     0
12     1
13     0
14     0
15    -1
16     0
17     0
18     0
19     0
20     0
21     0
22     0
23     0
24     0
25     0
26     0
27     0
28     0
29     0
30     0
31     0
32     1
33     0
34     0
35     0
36    -1

我尝试用-1替换值1的+24行中的每个值。
以下是所需的输出：

Bar numbers
7      1
8     -1
9      0
10     0
11     0
12     1
13     0
14     0
15    -1
16     0
17     0
18     0
19     0
20     0
21     0
22     0
23     0
24     0
25     0
26     0
27     0
28     0
29     0
30     0
31    -1
32     1
33     0
34     0
35     0
36    -1

索引31被替换为-1，因为索引7是1。与索引36相同（索引12是1）。在这种情况下，索引36的值保持不变。