code: def ungroupslice(groups,gslice):
    'this is a helper for contigsub.'
    'coordinate transform: takes a match from seqingroups() and transforms to ungrouped coordinates'
    eltsbefore=0
    for i in range(gslice[0]): eltsbefore+=len(groups[i])-1
    x=eltsbefore+gslice[1]; return [x-1,x+gslice[2]-1f ungroupslice(groups,gslice):
    'this is a helper for contigsub.'
    'coordinate transform: takes a match from seqingroups() and transforms to ungrouped coordinates'
    eltsbefore=0
    for i in range(gslice[0]): eltsbefore+=len(groups[i])-1
    x=eltsbefore+gslice[1]; return [x-1,x+gslice[2]-1]
docs: this is a helper for contigsub.