def add_aligned_intervals(al, alignedIvals):
    # for each pair of aligned intervals, save them into the alignment.
    for t in alignedIvals:
        # is 't' a marker object for start or end of a group of coordinates?
        if isinstance(t, (CoordsGroupStart, CoordsGroupEnd)):
            continue # ignore grouping markers

        (src, dest) = t
        al += src
        al[src][dest] = None                # save their alignment
This function takes the name of a python source file, expands all tabs to 4 spaces (for
dataset/ETHPy150Open cjlee112/pygr/pygr/nlmsa_utils.py/add_aligned_intervals--crossover with--dataset/ETHPy150Open jesolem/PCV/expand_tabs.py/expand_tabs