code: def intervals_to_bed(intervals):
      
      import re
      strand = re.compile('(.*):(.*)-(.*):(\+|-)')
      no_strand = re.compile('(.*):(.*)-(.*)')
      bed_lines = []
      s = False
      for i in intervals:
          m = strand.match(i)
          if m:
              bed_lines.append('\t'.join([m.group(x) for x in range(1, 5)]))
          else:
              m = no_strand.match(i)
              if m:
                  bed_lines.append('\t'.join([m.group(x) for x in range(1, 4)]))
      bt = pbt.BedTool('\n'.join(bed_lines) + '\n', from_string=True)
      return bt
docs: Convert list of intervals of format chr1:100-200 or chr1:100-200:+ to 
      BedTool object.
  
      Parameters
      ----------
      intervals : array-like
          List of intervals.
  
      Returns
      -------
      bt : pybedtools.BedTool
          BedTool with one line for each interval.