afni.nimh.nih.gov

The AFNI tool that allows you to do this is 3dTcat.

-tpattern PATTERN = Specify the timing pattern for the output
                       dataset, using patterns described in the
                       'to3d -help' output (alt+z, seq, alt-z2, etc).

If you want the "pure" python way of doing this - you could use nibable to read/write the NIFTI file and set_slice_times.

Per usual, the AFNI way is easier. You could certainly wrap the AFNI command in Python.