Create the output dataframe from input, how to filter for rows when target == 1 for the first time for each id, or in order words removing consecutive occurrence for each ids where target is 1 however keep all 0s in target before target = 1.

Input

```
ID   date         target
a1   2019-11-01   0
a1   2019-12-01   0
a1   2020-01-01   1
a1   2020-02-01   1
a1   2020-03-01   0
a2   2019-11-01   0
a2   2019-12-01   1
a2   2020-03-01   0
a2   2020-04-01   1

```

Output

```
ID   date         target
a1   2019-11-01   0
a1   2019-12-01   0
a1   2020-01-01   1
a2   2019-11-01   0
a2   2019-12-01   1

```