code: def merge_recs_headers(recs):
      '''
      take a list of recs [rec1,rec2,rec3....], each rec is a dictionary.
      make sure that all recs have the same headers.
      '''
      headers = []
      for rec in recs:
          keys = list(rec.keys())
          for key in keys:
              if key not in headers:
                  headers.append(key)
      for rec in recs:
          for header in headers:
              if header not in list(rec.keys()):
                  rec[header] = ""
      return recf merge_recs_headers(recs):
      '''
      take a list of recs [rec1,rec2,rec3....], each rec is a dictionary.
      make sure that all recs have the same headers.
      '''
      headers = []
      for rec in recs:
          keys = list(rec.keys())
          for key in keys:
              if key not in headers:
                  headers.append(key)
      for rec in recs:
          for header in headers:
              if header not in list(rec.keys()):
                  rec[header] = ""
      return recs
docs: take a list of recs [rec1,rec2,rec3....], each rec is a dictionary.
      make sure that all recs have the same headers.