任何人都可以建议一种在 python 中进行日志记录的方法：
感谢您的任何回复， 弗雷德
【问题讨论】：
encoding='bz2'参数。 （请注意，此“技巧”仅适用于 Python2。“bz2”不再被视为 Python3 中的编码。）maxBytes参数，日志文件在达到一定大小时会翻转。通过设置backupCount 参数，您可以控制保留多少翻转。这两个参数一起允许您控制日志文件占用的最大空间。您可能也可以将 TimeRotatingFileHandler 子类化以将此行为合并到其中。只是为了好玩，这里是您可以继承TimeRotatingFileHandler 的方法。当您运行下面的脚本时，它会将日志文件写入/tmp/log_rotate*。
time.sleep 的值较小（例如 0.1），日志文件会很快填满，达到 maxBytes 限制，然后滚动。
对于较大的time.sleep（例如 1.0），日志文件填满缓慢，未达到 maxBytes 限制，但在达到定时间隔（10 秒）时它们仍然会滚动。
以下所有代码均来自logging/handlers.py。我只是以最直接的方式将 TimeRotatingFileHandler 与 RotatingFileHandler 相结合。
import time
import re
import os
import stat
import logging
import logging.handlers as handlers
class SizedTimedRotatingFileHandler(handlers.TimedRotatingFileHandler):
"""
Handler for logging to a set of files, which switches from one file
to the next when the current file reaches a certain size, or at certain
timed intervals
"""
def __init__(self, filename, maxBytes=0, backupCount=0, encoding=None,
delay=0, when='h', interval=1, utc=False):
handlers.TimedRotatingFileHandler.__init__(
self, filename, when, interval, backupCount, encoding, delay, utc)
self.maxBytes = maxBytes
def shouldRollover(self, record):
"""
Determine if rollover should occur.
Basically, see if the supplied record would cause the file to exceed
the size limit we have.
"""
if self.stream is None: # delay was set...
self.stream = self._open()
if self.maxBytes > 0: # are we rolling over?
msg = "%s\n" % self.format(record)
# due to non-posix-compliant Windows feature
self.stream.seek(0, 2)
if self.stream.tell() + len(msg) >= self.maxBytes:
return 1
t = int(time.time())
if t >= self.rolloverAt:
return 1
return 0
def demo_SizedTimedRotatingFileHandler():
log_filename = '/tmp/log_rotate'
logger = logging.getLogger('MyLogger')
logger.setLevel(logging.DEBUG)
handler = SizedTimedRotatingFileHandler(
log_filename, maxBytes=100, backupCount=5,
when='s', interval=10,
# encoding='bz2', # uncomment for bz2 compression
)
logger.addHandler(handler)
for i in range(10000):
time.sleep(0.1)
logger.debug('i=%d' % i)
demo_SizedTimedRotatingFileHandler()
【讨论】：
在旋转期间压缩日志文件的另一种方法（python 3.3 中的新方法）是使用 BaseRotatingHandler（以及所有继承的）类属性 rotator 例如：
import gzip
import os
import logging
import logging.handlers
class GZipRotator:
def __call__(self, source, dest):
os.rename(source, dest)
f_in = open(dest, 'rb')
f_out = gzip.open("%s.gz" % dest, 'wb')
f_out.writelines(f_in)
f_out.close()
f_in.close()
os.remove(dest)
logformatter = logging.Formatter('%(asctime)s;%(levelname)s;%(message)s')
log = logging.handlers.TimedRotatingFileHandler('debug.log', 'midnight', 1, backupCount=5)
log.setLevel(logging.DEBUG)
log.setFormatter(logformatter)
log.rotator = GZipRotator()
logger = logging.getLogger('main')
logger.addHandler(log)
logger.setLevel(logging.DEBUG)
....
更多你可以看到here。
【讨论】：
with 或 finally 构造
除了 unutbu 的回答：这里是如何修改 TimedRotatingFileHandler 以使用 zip 文件进行压缩。
import logging
import logging.handlers
import zipfile
import codecs
import sys
import os
import time
import glob
class TimedCompressedRotatingFileHandler(logging.handlers.TimedRotatingFileHandler):
"""
Extended version of TimedRotatingFileHandler that compress logs on rollover.
"""
def doRollover(self):
"""
do a rollover; in this case, a date/time stamp is appended to the filename
when the rollover happens. However, you want the file to be named for the
start of the interval, not the current time. If there is a backup count,
then we have to get a list of matching filenames, sort them and remove
the one with the oldest suffix.
"""
self.stream.close()
# get the time that this sequence started at and make it a TimeTuple
t = self.rolloverAt - self.interval
timeTuple = time.localtime(t)
dfn = self.baseFilename + "." + time.strftime(self.suffix, timeTuple)
if os.path.exists(dfn):
os.remove(dfn)
os.rename(self.baseFilename, dfn)
if self.backupCount > 0:
# find the oldest log file and delete it
s = glob.glob(self.baseFilename + ".20*")
if len(s) > self.backupCount:
s.sort()
os.remove(s[0])
#print "%s -> %s" % (self.baseFilename, dfn)
if self.encoding:
self.stream = codecs.open(self.baseFilename, 'w', self.encoding)
else:
self.stream = open(self.baseFilename, 'w')
self.rolloverAt = self.rolloverAt + self.interval
if os.path.exists(dfn + ".zip"):
os.remove(dfn + ".zip")
file = zipfile.ZipFile(dfn + ".zip", "w")
file.write(dfn, os.path.basename(dfn), zipfile.ZIP_DEFLATED)
file.close()
os.remove(dfn)
if __name__=='__main__':
## Demo of using TimedCompressedRotatingFileHandler() to log every 5 seconds,
## to one uncompressed file and five rotated and compressed files
os.nice(19) # I always nice test code
logHandler = TimedCompressedRotatingFileHandler("mylog", when="S",
interval=5, backupCount=5) # Total of six rotated log files, rotating every 5 secs
logFormatter = logging.Formatter(
fmt='%(asctime)s.%(msecs)03d %(message)s',
datefmt='%Y-%m-%d %H:%M:%S'
)
logHandler.setFormatter(logFormatter)
mylogger = logging.getLogger('MyLogRef')
mylogger.addHandler(logHandler)
mylogger.setLevel(logging.DEBUG)
# Write lines non-stop into the logger and rotate every 5 seconds
ii = 0
while True:
mylogger.debug("Test {0}".format(ii))
ii += 1
【讨论】：
rotate 方法中检查的处理程序类上定义 rotator 属性比覆盖 doRollover 更容易和灵活。
请注意：python 3 中的类签名已更改。这是我的 python 3.6 工作示例
import logging.handlers
import os
import zlib
def namer(name):
return name + ".gz"
def rotator(source, dest):
print(f'compressing {source} -> {dest}')
with open(source, "rb") as sf:
data = sf.read()
compressed = zlib.compress(data, 9)
with open(dest, "wb") as df:
df.write(compressed)
os.remove(source)
err_handler = logging.handlers.TimedRotatingFileHandler('/data/errors.log', when="M", interval=1,
encoding='utf-8', backupCount=30, utc=True)
err_handler.rotator = rotator
err_handler.namer = namer
logger = logging.getLogger("Rotating Log")
logger.setLevel(logging.ERROR)
logger.addHandler(err_handler)
【讨论】：
我想现在加入派对为时已晚，但我就是这样做的。我创建了一个继承logging.handlers.RotatingFileHandler 类的新类，并在移动文件之前添加了几行gzip 文件。
https://github.com/rkreddy46/python_code_reference/blob/master/compressed_log_rotator.py
#!/usr/bin/env python
# Import all the needed modules
import logging.handlers
import sys
import time
import gzip
import os
import shutil
import random
import string
__version__ = 1.0
__descr__ = "This logic is written keeping in mind UNIX/LINUX/OSX platforms only"
# Create a new class that inherits from RotatingFileHandler. This is where we add the new feature to compress the logs
class CompressedRotatingFileHandler(logging.handlers.RotatingFileHandler):
def doRollover(self):
"""
Do a rollover, as described in __init__().
"""
if self.stream:
self.stream.close()
if self.backupCount > 0:
for i in range(self.backupCount - 1, 0, -1):
sfn = "%s.%d.gz" % (self.baseFilename, i)
dfn = "%s.%d.gz" % (self.baseFilename, i + 1)
if os.path.exists(sfn):
# print "%s -> %s" % (sfn, dfn)
if os.path.exists(dfn):
os.remove(dfn)
os.rename(sfn, dfn)
dfn = self.baseFilename + ".1.gz"
if os.path.exists(dfn):
os.remove(dfn)
# These two lines below are the only new lines. I commented out the os.rename(self.baseFilename, dfn) and
# replaced it with these two lines.
with open(self.baseFilename, 'rb') as f_in, gzip.open(dfn, 'wb') as f_out:
shutil.copyfileobj(f_in, f_out)
# os.rename(self.baseFilename, dfn)
# print "%s -> %s" % (self.baseFilename, dfn)
self.mode = 'w'
self.stream = self._open()
# Specify which file will be used for our logs
log_filename = "/Users/myname/Downloads/test_logs/sample_log.txt"
# Create a logger instance and set the facility level
my_logger = logging.getLogger()
my_logger.setLevel(logging.DEBUG)
# Create a handler using our new class that rotates and compresses
file_handler = CompressedRotatingFileHandler(filename=log_filename, maxBytes=1000000, backupCount=10)
# Create a stream handler that shows the same log on the terminal (just for debug purposes)
view_handler = logging.StreamHandler(stream=sys.stdout)
# Add all the handlers to the logging instance
my_logger.addHandler(file_handler)
my_logger.addHandler(view_handler)
# This is optional to beef up the logs
random_huge_data = "".join(random.choice(string.ascii_letters) for _ in xrange(10000))
# All this code is user-specific, write your own code if you want to play around
count = 0
while True:
my_logger.debug("This is the message number %s" % str(count))
my_logger.debug(random_huge_data)
count += 1
if count % 100 == 0:
count = 0
time.sleep(2)
【讨论】：
要复制文件，请 gzip 复制的文件（使用纪元时间），然后以不会扰乱日志记录模块的方式清除现有文件：
import gzip
import logging
import os
from shutil import copy2
from time import time
def logRoll(logfile_name):
log_backup_name = logfile_name + '.' + str(int(time()))
try:
copy2(logfile_name, log_backup_name)
except IOError, err:
logging.debug(' No logfile to roll')
return
f_in = open(log_backup_name, 'rb')
f_out = gzip.open(log_backup_name + '.gz', 'wb')
f_out.writelines(f_in)
f_out.close()
f_in.close()
os.remove(log_backup_name)
f=open(logfile_name, 'w')
f.close()
【讨论】：
我认为最好的选择是使用TimedRotatingFileHandler 的当前实现，并将日志文件重命名为旋转版本后，只需压缩它：
import zipfile
import os
from logging.handlers import TimedRotatingFileHandler
class TimedCompressedRotatingFileHandler(TimedRotatingFileHandler):
"""
Extended version of TimedRotatingFileHandler that compress logs on rollover.
"""
def find_last_rotated_file(self):
dir_name, base_name = os.path.split(self.baseFilename)
file_names = os.listdir(dir_name)
result = []
prefix = '{}.20'.format(base_name) # we want to find a rotated file with eg filename.2017-12-12... name
for file_name in file_names:
if file_name.startswith(prefix) and not file_name.endswith('.zip'):
result.append(file_name)
result.sort()
return result[0]
def doRollover(self):
super(TimedCompressedRotatingFileHandler, self).doRollover()
dfn = self.find_last_rotated_file()
dfn_zipped = '{}.zip'.format(dfn)
if os.path.exists(dfn_zipped):
os.remove(dfn_zipped)
with zipfile.ZipFile(dfn_zipped, 'w') as f:
f.write(dfn, dfn_zipped, zipfile.ZIP_DEFLATED)
os.remove(dfn)
【讨论】：
这是我的解决方案（修改自evgenek），简单且在压缩大量日志文件时不会阻塞python代码：
class GZipRotator:
def __call__(self, source, dest):
os.rename(source, dest)
subprocess.Popen(['gzip', dest])
【讨论】：
我在下面添加了一个解决方案，我基本上是在压缩旧的 将日志备份到带有时间戳的 zip 文件中。使用一个额外的变量 称为 ZipbackupCount。 # 没有要压缩的旧文件
例如我们有这样的日志。 (backupcount = 5 和 ZipbackupCount = 2)
a.log.1
a.log.2
a.log.3
a.log.4
a.log.11-09-2020-11-11-11.zip
一旦备份日志计数达到 5，它就会触发将 a.log.5 和 a.log.4 压缩到以上 zip 并继续。
import os
import datetime
import gzip
import logging.handlers
import zipfile
from config.config import PROJECT_PATH, LOG_DIR, LOG_FILE_NAME, LOG_FILESIZE
class NewRotatingFileHandler(logging.handlers.RotatingFileHandler):
def __init__(self, filename, **kws):
backupCount = kws.get('backupCount', 0)
self.backup_count = backupCount
self.ZipbackupCount = kws.pop('ZipbackupCount', 0)
self.file_name = filename
self.log_dir = os.path.split(self.file_name)[0]
self.log_file_name = os.path.split(self.file_name)[-1]
logging.handlers.RotatingFileHandler.__init__(self, filename, **kws)
def doArchive(self, old_log):
with open(old_log) as log:
with gzip.open(old_log + '.gz', 'wb') as comp_log:
comp_log.writelines(log)
os.remove(old_log)
def doRollover(self):
super(NewRotatingFileHandler, self).doRollover()
zip_file_name = self.log_file_name + "." + datetime.datetime.now().strftime("%d-%m-%Y-%H-%M-%S") + ".zip"
if os.path.exists(self.rotation_filename("%s.%d" % (self.baseFilename, self.backupCount))) and self.ZipbackupCount > 0 and self.file_name:
with zipfile.ZipFile(os.path.join(self.log_dir, zip_file_name), "w", zipfile.ZIP_DEFLATED, allowZip64=True) as zf:
for i in range(self.backupCount, self.backupCount - self.ZipbackupCount, -1):
sfn = self.rotation_filename("%s.%d" % (self.baseFilename, i))
if os.path.exists(sfn):
zf.write(sfn, "%s.%d" % (self.log_file_name, i))
os.remove(sfn)
else:
continue
zf.close()
# handler = NewRotatingFileHandler(filename=os.path.join(PROJECT_PATH, LOG_DIR, LOG_FILE_NAME),
# maxBytes=LOG_FILESIZE, backupCount=5, ZipbackupCount=2)
#
# handler.doRollover()
【讨论】：
我看到很多答案都集中在覆盖处理程序类的 doRollover 方法上，这很好并且可以工作，但我认为更简洁和推荐的解决方案是在检查的处理程序类上定义 rotator 属性在rotate 方法中而不是覆盖doRollover。
def setup_logger():
def bz2namer(name):
return name + ".bz2"
def bzip_rotator(source, dest):
with open(source, "rb") as sf:
data = sf.read()
compressed = bz2.compress(data, 9)
with open(dest, "wb") as df:
df.write(compressed)
os.remove(source)
log = logging.getLogger("myapp")
file_handler = RotatingFileHandler(filename="app.log", backupCount=10, maxBytes=10000000)
file_handler.rotator = bzip_rotator
file_handler.namer = bz2namer
_log_format = "%(asctime)s [%(process)d] [%(levelname)s] [%(filename)s: %(funcName)s] - %(message)s "
log_formatter = logging.Formatter(_log_format, datefmt="%Y-%m-%d %H:%M:%S")
file_handler.setFormatter(log_formatter)
file_handler.setLevel(logging.DEBUG)
log.propagate = False
log.addHandler(file_handler)
【讨论】：