def common_time_extrator(self, string):
        """一般时间抽取，即年月日分别出现

        Keyword arguments:
        string              -- 含有时间的文本，str类型
        """

        try:
            if not self.year_check:
                str_year = int(re.search('(\d{4})年', string).group(1))
                check_year = datetime.datetime.now().year
                if str_year in range(1970, check_year + 1):
                    self.year = str_year
                    self.year_check = True
        except:
            pass
        try:
            if not self.month_check:
                str_month = int(re.search('(\d{1,2})月', string).group(1))
                if str_month in range(1, 13):
                    self.month = str_month
                    self.month_check = True
        except:
            pass
        try:
            if not self.day_check:
                str_day = int(re.search('(\d{1,2})[日号]', string).group(1))
                if str_day in range(1, 32):
                    self.day = str_day
                    self.day_check = True
        except:
            pass