update init

mrdna/readers/segmentmodel_from_scadnano.py

 # -*- coding: utf-8 -*-
 import numpy as np
-import os,sys
-from glob import glob
-import re
 import pandas as pd
 pd.options.mode.chained_assignment = None  # default='warn'
 from .segmentmodel_from_lists import model_from_basepair_stack_3prime
 import scadnano as sc
 from ..arbdmodel.coords import readArbdCoords, readAvgArbdCoords, rotationAboutAxis
-from ..segmentmodel import SegmentModel, SingleStrandedSegment, DoubleStrandedSegment
 from ..model.dna_sequence import m13 as m13seq
-import json
-import re
-import pdb