2021-01-22 Python TimedRotatingFileHandler 修改suffix后无法自动删除文件

喜欢ヅ旅行 2023-01-09 15:59 228阅读 0赞

### Python TimedRotatingFileHandler 修改suffix后无法自动删除文件 ###

TimedRotatingFileHandler 用法

“S”: Seconds
    “M”: Minutes
    “H”: Hours
    “D”: Days
    “W”: Week day (0=Monday)
    “midnight”: Roll over at midnight

设计1s一个日志，超过3个删除

log = logging.getLogger()
    	log.setLevel(logging.ERROR)  # 日志等级为ERROR
    	
    	fh = logging.handlers.TimedRotatingFileHandler("log", when='S', interval=1, backupCount=3)
    	fh.suffix = "%Y-%m-%d_%H-%M-%S.log"
    	formatter = logging.Formatter('[%(asctime)s] - %(filename)s [Line:%(lineno)d] - [%(levelname)s]-[thread:%(thread)s]-[process:%(process)s] - %(message)s') 
    	fh.setFormatter(formatter)
    	log.addHandler(fh)
    	i = 0
    	while i < 100000000:
    	    sleep(0.1)
    	    log.error("记录" + str(i))
    	    i = i + 1

结果是并不会删除

![在这里插入图片描述][20181101133936257.png]

查看TimedRotatingFileHandler的源码

def __init__(self, filename, when='h', interval=1, backupCount=0, encoding=None, delay=False, utc=False):
            BaseRotatingHandler.__init__(self, filename, 'a', encoding, delay)
            self.when = when.upper()
            self.backupCount = backupCount
            self.utc = utc      
            if self.when == 'S':
                self.interval = 1 # one second
                self.suffix = "%Y-%m-%d_%H-%M-%S"
                self.extMatch = r"^\d{4}-\d{2}-\d{2}_\d{2}-\d{2}-\d{2}$"
            elif self.when == 'M':
                self.interval = 60 # one minute
                self.suffix = "%Y-%m-%d_%H-%M"
                self.extMatch = r"^\d{4}-\d{2}-\d{2}_\d{2}-\d{2}$"
            elif self.when == 'H':
                self.interval = 60 * 60 # one hour
                self.suffix = "%Y-%m-%d_%H"
                self.extMatch = r"^\d{4}-\d{2}-\d{2}_\d{2}$"
            elif self.when == 'D' or self.when == 'MIDNIGHT':
                self.interval = 60 * 60 * 24 # one day
                self.suffix = "%Y-%m-%d"
                self.extMatch = r"^\d{4}-\d{2}-\d{2}$"
            elif self.when.startswith('W'):
                self.interval = 60 * 60 * 24 * 7 # one week
                if len(self.when) != 2:
                    raise ValueError("You must specify a day for weekly rollover from 0 to 6 (0 is Monday): %s" % self.when)
                if self.when[1] < '0' or self.when[1] > '6':
                    raise ValueError("Invalid day specified for weekly rollover: %s" % self.when)
                self.dayOfWeek = int(self.when[1])
                self.suffix = "%Y-%m-%d"
                self.extMatch = r"^\d{4}-\d{2}-\d{2}$"
            else:
                raise ValueError("Invalid rollover interval specified: %s" % self.when)
    
            self.extMatch = re.compile(self.extMatch)
            self.interval = self.interval * interval # multiply by units requested
            if os.path.exists(filename):
                t = os.stat(filename)[ST_MTIME]
            else:
                t = int(time.time())
            self.rolloverAt = self.computeRollover(t)

关键是下面的几行

self.suffix = "%Y-%m-%d_%H-%M-%S"
    self.extMatch = r"^\d{4}-\d{2}-\d{2}_\d{2}-\d{2}-\d{2}$"
    ······
    ······
    self.extMatch = re.compile(self.extMatch)

默认设置when类型后，suffix是固定的，匹配的正则也是源码里写好的，所以当修改suffix后，必须连带正则一并修改

最终代码如下

log = logging.getLogger()
    log.setLevel(logging.ERROR)  # 日志等级为ERROR
    
    fh = logging.handlers.TimedRotatingFileHandler("log", when='S', interval=1, backupCount=3)
    fh.suffix = "%Y-%m-%d_%H-%M-%S.log"
    fh.extMatch = r"^\d{4}-\d{2}-\d{2}_\d{2}-\d{2}-\d{2}.log$"
    fh.extMatch = re.compile(fh.extMatch)
    formatter = logging.Formatter('[%(asctime)s] - %(filename)s [Line:%(lineno)d] - [%(levelname)s]-[thread:%(thread)s]-[process:%(process)s] - %(message)s') 
    fh.setFormatter(formatter)
    log.addHandler(fh)
    i = 0
    while i < 100000000:
        sleep(0.1)
        log.error("记录" + str(i))
        i = i + 1

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FpbmdmZW5neGQx_size_16_color_FFFFFF_t_70][]

[20181101133936257.png]: /images/20221119/df1e22cb650046fb8f275ef7e10bf6c0.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FpbmdmZW5neGQx_size_16_color_FFFFFF_t_70]: /images/20221119/7edd06a8cbed48178d813069eb92443c.png