code: def QA_util_getBetweenMonth(from_date, to_date):
      
      date_list = {}
      begin_date = datetime.datetime.strptime(from_date, "%Y-%m-%d")
      end_date = datetime.datetime.strptime(to_date, "%Y-%m-%d")
      while begin_date <= end_date:
          date_str = begin_date.strftime("%Y-%m")
          date_list[date_str] = ['%d-%d-01' % (begin_date.year, begin_date.month),
                                 '%d-%d-%d' % (begin_date.year, begin_date.month,
                                               calendar.monthrange(begin_date.year, begin_date.month)[1])]
          begin_date = QA_util_get_1st_of_next_month(begin_date)
      return(date_list)
docs: #返回所有月份，以及每月的起始日期、结束日期，字典格式