is there any solution to get last record from stdout?

hi i am jeff

i am now using embulk with little weird way.

1. a batch python script generates some dynamic yaml files every some minutes.
2. reads diff.yaml file which is generated by last batch job.
3. applies last record into dynamic yaml file of 1.
4. executes embulk several times with dynamic yaml files through python bash interface.
5. drops diff.yaml file. within it, there is last record.

is there any better way to get last record?
or to call embulk in code way? not in bash way?

thanks