After some data preprocessing, I am stuck with merging the datasets. What I would like to do is to merge all dates under the same column as following in a row order according to same batch number. Normally it was stacked data, then I have unstacked according to process steps (40,42,50). Then my intention is to take the time difference of two columns as minutes.
DATASET:
process 40-------------------42-----------------------50
index batch
64177 699042 NaT------------------2019-01-10 18:28:05-------NaT
171272 699042 NaT------------------NaT-------------------- 2019-01-10 18:28:20
120655 699042 2019-01-10 17:40:09--NaT----------------------NaT
120656 699043 2019-01-10 17:40:09--NaT----------------------NaT
67362 699043 NaT------------------2019-01-10 20:43:25-------NaT
168373 699043 NaT------------------NaT-----------------------2019-01-10 20:43:33
WHAT I WANT IS:
process 40-------------------42-----------------------50
batch
699042 2019-01-10 17:40:09-----2019-01-10 18:28:05-------2019-01-10 18:28:20
699043 2019-01-10 17:40:09----2019-01-10 20:43:25-------2019-01-10 20:43:33