1
我试图根据两个条件在熊猫中创建条件运行总和。有条件的运行计数熊猫
import pandas as pd
ID = [1,1,1,2,2,3,4]
after = ['A','B','B','A','A','B','A']
before = ['A','B','B','A','A','B','A']
df = pd.DataFrame([ID, before,after]).T
df.columns = ['ID','before','after']
的数据是这样的:
ID before after
0 1 A A
1 1 B B
2 1 B B
3 2 A A
4 2 A A
5 3 B B
6 4 A A
我则想看看有多长的ID已为B的前值,我的尝试:
df['time_on_b'] = (df.groupby('before')['ID'].cumcount()+1).where(df['before']=='B',0)
这使me:
ID before after time_on_b
0 1 A A 0
1 1 B B 1
2 1 B B 2
3 2 A A 0
4 2 A A 0
5 3 B B 3
6 4 A A 0
i处理输出如下:
ID before after time_on_b
0 1 A A 0
1 1 B B 1
2 1 B B 2
3 2 A A 0
4 2 A A 0
5 3 B B 1
6 4 A A 0
正如你可以看到,作为标识的变化我想time_on_b重置所以它给了我1的值,而不是3