zero padding variable length of array in uproot

Question

I need a memory efficient way to zero pad uneven array size per event according to largest array in a tree. Is there any way available to do that in uproot?

Answer 1

jagged_array.pad(max_length).fillna(0)

If you need to find the maximum, you can

jagged_array.counts.max()

If you then need to turn it into pure NumPy, use regular().