so I have a series, I want to cumsum, but start over every time I hit a 0, somthing like this:

any ideas? (pandas, pure python, other)

CodePudding user response：

Use df['orig'].eq(0).cumsum() to generate groups starting on each 0, then cumcount to get the increasing values:

df['result'] = df.groupby(df['orig'].eq(0).cumsum()).cumcount()

output:

    orig  wanted result  result
0      0              0       0
1      1              1       1
2      1              2       2
3      1              3       3
4      1              4       4
5      1              5       5
6      1              6       6
7      0              0       0
8      1              1       1
9      1              2       2
10     1              3       3
11     0              0       0
12     1              1       1
13     1              2       2
14     1              3       3
15     1              4       4
16     1              5       5
17     1              6       6

Intermediate:

df['orig'].eq(0).cumsum()

0     1
1     1
2     1
3     1
4     1
5     1
6     1
7     2
8     2
9     2
10    2
11    3
12    3
13    3
14    3
15    3
16    3
17    3
Name: orig, dtype: int64

CodePudding user response：

import pandas as pd
condition = df.Orig.eq(0)
df['reset'] = condition.cumsum()