Summary of python logging Module
- 2021-07-10 20:22:31
- OfStack
Log level
Specific parameter meaning in logging. basicConfig () function
Formatting information for format parameters
| 参数 | 描述 |
|---|---|
| %(name)s | Logger的名字 |
| %(levelno)s | 数字形式的日志级别 |
| %(levelname)s | 文本形式的日志级别 |
| %(pathname)s | 调用日志输出函数的模块的完整路径名，可能没有 |
| %(filename)s | 调用日志输出函数的模块的文件名 |
| %(module)s | 调用日志输出函数的模块名 |
| %(funcName)s | 调用日志输出函数的函数名 |
| %(lineno)d | 调用日志输出函数的语句所在的代码行 |
| %(created)f | 当前时间，用UNIX标准的表示时间的浮 点数表示 |
| %(relativeCreated)d | 输出日志信息时的，自Logger创建以 来的毫秒数 |
| %(asctime)s | 字符串形式的当前时间。默认格式是 “2003-07-08 16:49:45,896”。逗号后面的是毫秒 |
| %(thread)d | 线程ID。可能没有 |
| %(threadName)s | 线程名。可能没有 |
| %(process)d | 进程ID。可能没有 |
| %(message)s | 用户输出的消息 |
Use logging to print logs to standard output
import logging
logging.debug('debug message')
logging.info('info message')
logging.warning('warning message')
Enter the log to a file using logging. baseConfig ()
import os
logging.basicConfig(
filename=os.path.join(os.getcwd(),'all.log'),
level=logging.DEBUG,
format='%(asctime)s %(filename)s : %(levelname)s %(message)s', # Defining Output log Format of
filemode='a',
datefmt='%Y-%m-%d %A %H:%M:%S',
)
logging.debug('this is a message')
Custom Logger
Setting the log write file to be automatically split by log file size
import logging
from logging import handlers
class Logger(object):
level_relations = {
'debug': logging.DEBUG,
'info': logging.INFO,
'warning': logging.WARNING,
'error': logging.ERROR,
'crit': logging.CRITICAL
}
def __init__(self, filename, level='info', when='D', backCount=3,
fmt='%(asctime)s - %(pathname)s[line:%(lineno)d] - %(levelname)s: %(message)s'):
self.logger = logging.getLogger(filename)
format_str = logging.Formatter(fmt) # Format the log
self.logger.setLevel(self.level_relations.get(level)) # Setting Log Levels
# Output log to console
stream_handler = logging.StreamHandler()
stream_handler.setFormatter(format_str)
self.logger.addHandler(stream_handler)
# Log writes to file by file size
# 1MB = 1024 * 1024 bytes
# Here set the file size to 500MB
rotating_file_handler = handlers.RotatingFileHandler(
filename=filename, mode='a', maxBytes=1024 * 1024 * 500, backupCount=5, encoding='utf-8')
rotating_file_handler.setFormatter(format_str)
self.logger.addHandler(rotating_file_handler)
log = Logger('all.log', level='info')
log.logger.info('[ Test log] hello, world')
Automatically generate log files by interval date
import logging
from logging import handlers
class Logger(object):
level_relations = {
'debug': logging.DEBUG,
'info': logging.INFO,
'warning': logging.WARNING,
'error': logging.ERROR,
'crit': logging.CRITICAL
}
def __init__(self, filename, level='info', when='D', backCount=3,
fmt='%(asctime)s - %(pathname)s[line:%(lineno)d] - %(levelname)s: %(message)s'):
self.logger = logging.getLogger(filename)
format_str = logging.Formatter(fmt) # Format the log
self.logger.setLevel(self.level_relations.get(level)) # Setting Log Levels
# Write to a file
# Processor that automatically generates files at specified intervals
timed_rotating_file_handler = handlers.TimedRotatingFileHandler(
filename=filename, when=when, backupCount=backCount, encoding='utf-8')
# Instantiation TimedRotatingFileHandler
# interval Is the time interval, backupCount Is the number of backup files. If this number is exceeded, it will be automatically deleted. when Is the time unit of interval, and there are the following units:
# S Seconds
# M Points
# H Hours,
# D God,
# W Every week ( interval==0 The hour stands for the week 1 )
# midnight Every morning
timed_rotating_file_handler.setFormatter(format_str) # Format writes in files
self.logger.addHandler(timed_rotating_file_handler)
# Output to the screen
stream_handler = logging.StreamHandler()
stream_handler.setFormatter(format_str)
self.logger.addHandler(stream_handler)
log = Logger('all.log', level='info')
log.logger.info('[ Test log] hello, world')
Application of logging Module in Flask
I read a lot of Flask documents about logging in the process of using Flask, but it is not very convenient to use, so I wrote the following log module according to the official document of Flask, so as to integrate it into Flask.
restful api Project Directory:
.
-- apps_api
The -- common
The -- models
The Off- resources
-- logs
-- migrations
The Off- versions
-- static
-- templates
-- test
Off- utils
Off- app.py
Off- config.py
Off- exts.py
Off- log.py
Off- manage.py
Off- run.py
Off- README.md
Off- requirements.txtlog. py file
# -*- coding: utf-8 -*-
import logging
from flask.logging import default_handler
import os
from logging.handlers import RotatingFileHandler
from logging import StreamHandler
BASE_DIR = os.path.dirname(os.path.abspath(__file__))
LOG_PATH = os.path.join(BASE_DIR, 'logs')
LOG_PATH_ERROR = os.path.join(LOG_PATH, 'error.log')
LOG_PATH_INFO = os.path.join(LOG_PATH, 'info.log')
LOG_PATH_ALL = os.path.join(LOG_PATH, 'all.log')
# Maximum log file 100MB
LOG_FILE_MAX_BYTES = 100 * 1024 * 1024
# The number of rotations is 10 A
LOG_FILE_BACKUP_COUNT = 10
class Logger(object):
def init_app(self, app):
# Remove the default handler
app.logger.removeHandler(default_handler)
formatter = logging.Formatter(
'%(asctime)s [%(thread)d:%(threadName)s] [%(filename)s:%(module)s:%(funcName)s] '
'[%(levelname)s]: %(message)s'
)
# Output the log to a file
# 1 MB = 1024 * 1024 bytes
# Set the log file size here to 500MB , more than 500MB Automatically start writing new log files, archiving history files
file_handler = RotatingFileHandler(
filename=LOG_PATH_ALL,
mode='a',
maxBytes=LOG_FILE_MAX_BYTES,
backupCount=LOG_FILE_BACKUP_COUNT,
encoding='utf-8'
)
file_handler.setFormatter(formatter)
file_handler.setLevel(logging.INFO)
stream_handler = StreamHandler()
stream_handler.setFormatter(formatter)
stream_handler.setLevel(logging.INFO)
for logger in (
# You can also add more logging modules here, see Flask Official documents
app.logger,
logging.getLogger('sqlalchemy'),
logging.getLogger('werkzeug')
):
logger.addHandler(file_handler)
logger.addHandler(stream_handler)Add the log module to the exts. py extension file
# encoding: utf-8
from log import Logger
logger = Logger()Introduce the logger module in the app. py file, which is the factory module of create_app.
# encoding: utf-8
from flask import Flask
from config import CONFIG
from exts import logger
def create_app():
app = Flask(__name__)
# Load configuration
app.config.from_object(CONFIG)
# Initialization logger
logger.init_app(app)
return appRun run. py
# -*- coding: utf-8 -*-
from app import create_app
app = create_app()
if __name__ == '__main__':
app.run()
$ python run.py
* Serving Flask app "app" (lazy loading)
* Environment: production
WARNING: This is a development server. Do not use it in a production deployment.
Use a production WSGI server instead.
* Debug mode: on
2019-07-08 08:15:50,396 [140735687508864:MainThread] [_internal.py:_internal:_log] [INFO]: * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
2019-07-08 08:15:50,397 [140735687508864:MainThread] [_internal.py:_internal:_log] [INFO]: * Restarting with stat
2019-07-08 08:15:50,748 [140735687508864:MainThread] [_internal.py:_internal:_log] [WARNING]: * Debugger is active!
2019-07-08 08:15:50,755 [140735687508864:MainThread] [_internal.py:_internal:_log] [INFO]: * Debugger PIN: 234-828-739