How I do I get a second sample from a dataset in Python without getting duplication from a first sample?

I have a python dataset that I have managed to take a sample from and put in a second dataset. After that I will need to produce another sample from the original dataset but I do not want any of the first sample to come up again. Ideally this would need any flag would only be there for a year so it can then be sampled again after that time has elapsed.