logging模块

Python中有一个模块logging,可以直接记录日志

#   日志级别
# CRITICAL 50
# ERROR    40
# WARNING  30
# INFO     20
# DEBUG    10

  

logging.basicConfig()函数中的具体参数:
filename:   指定的文件名创建FiledHandler,这样日志会被存储在指定的文件中;
filemode:   文件打开方式,在指定了filename时使用这个参数,默认值为“w”还可指定为“a”;
format:      指定handler使用的日志显示格式;
datefmt:    指定日期时间格式。,格式参考strftime时间格式化(下文)
level:        设置rootlogger的日志级别
stream:     用指定的stream创建StreamHandler。可以指定输出到sys.stderr,sys.stdout或者文件,默认为sys.stderr。
                  若同时列出了filename和stream两个参数,则stream参数会被忽略。
 
format参数中可能用到的格式化信息:

%(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

二、logging模块测试

1、打印日志到标准输出中

import logging
logging.debug('debug message')
logging.info('info message')
logging.warning('warning message')

输出结果

C:\Users\Administrator\AppData\Local\Programs\Python\Python36\python.exe D:/pyworkpeace/tupian.py 'https://www.tianyancha.com/login'
WARNING:root:warning message

Process finished with exit code 0

可以看出默认情况下Python的logging模块将日志打印到了标准输出中,且只显示了大于等于WARNING级别的日志。默认的日志的格式为:

日志级别:Logger名称:用户输出消息

2、将日志文件输入到文件中

import os
logging.basicConfig(filename=os.path.join(os.getcwd(),'log.txt'),level=logging.DEBUG)
logging.debug('this is a message')

运行这三行代码后会在安装Python的目录中出现一个log.txt文件,文件内容

DEBUG:root:this is a message
DEBUG:root:debug message

3、自定义格式,输出日志文件

复制代码
# -*-coding:utf-8-*-

import logging


def console_out(logFilename):
    ''''' Output log to file and console '''
    # Define a Handler and set a format which output to file
    logging.basicConfig(
        level=logging.DEBUG,  # 定义输出到文件的log级别,大于此级别的都被输出
        format='%(asctime)s  %(filename)s : %(levelname)s  %(message)s',  # 定义输出log的格式
        datefmt='%Y-%m-%d %A %H:%M:%S',  # 时间
        filename=logFilename,  # log文件名
        filemode='w')  # 写入模式“w”或“a”
    # Define a Handler and set a format which output to console
    console = logging.StreamHandler()  # 定义console handler
    console.setLevel(logging.INFO)  # 定义该handler级别
    formatter = logging.Formatter('%(asctime)s  %(filename)s : %(levelname)s  %(message)s')  # 定义该handler格式
    console.setFormatter(formatter)
    # Create an instance
    logging.getLogger().addHandler(console)  # 实例化添加handler

    # Print information              # 输出日志级别
    logging.debug('logger debug message')
    logging.info('logger info message')
    logging.warning('logger warning message')
    logging.error('logger error message')
    logging.critical('logger critical message')


if __name__ == "__main__":
    console_out('logging.log')
复制代码

输出结果:

此时也会自动生成一个日志文件,日志文件和运行文件在同一个文件夹中,文件名logging.log

2017-10-23 Monday 11:37:59 hgghf : DEBUG logger debug message
2017-10-23 Monday 11:37:59 hgghf : INFO logger info message
2017-10-23 Monday 11:37:59 hgghf : WARNING logger warning message
2017-10-23 Monday 11:37:59 hgghf : ERROR logger error message
2017-10-23 Monday 11:37:59 hgghf : CRITICAL logger critical message

修改输出路径:

filename='/tmp/test1.log',  # log文件名
当将脚本中这行代码换一下,那么我们输出日志的路径地址就换成了D:\tmp
下面的方式同样可以达到上述结果

 4、自定义输出位置

复制代码
import logging  
logging.basicConfig(level=logging.DEBUG,  
                    format='%(asctime)s %(filename)s[line:%(lineno)d] %(levelname)s %(message)s',  
                    datefmt='%a, %d %b %Y %H:%M:%S',  
                    filename='/tmp/test.log',  
                    filemode='w')  
  
logging.debug('debug message')  
logging.info('info message')  
logging.warning('warning message')  
logging.error('error message')  
logging.critical('critical message') 
复制代码

由于运行脚本放在D:\pyworkpeace\下,输出文件在D盘tmp文件夹下test.log,内容如下:

Mon, 23 Oct 2017 15:00:05 tupian.py[line:11] DEBUG debug message
Mon, 23 Oct 2017 15:00:05 tupian.py[line:12] INFO info message
Mon, 23 Oct 2017 15:00:05 tupian.py[line:13] WARNING warning message
Mon, 23 Oct 2017 15:00:05 tupian.py[line:14] ERROR error message
Mon, 23 Oct 2017 15:00:05 tupian.py[line:15] CRITICAL critical message

5.logging.basicConfig常用设置

# 添加日志

logging.basicConfig(
    level=logging.INFO,  # 定义输出到文件的log级别,大于此级别的都被输出
    format='%(asctime)s  %(filename)s  %(levelname)s : %(message)s',  # 定义输出log的格式
    datefmt='%Y-%m-%d %H:%M:%S',  # 时间
    filename='baidu.log',  # log文件名
    filemode='a', )  # 写入模式“w”或“a”



# 输入日志信息
import logging
import time

logging.basicConfig(
    level=logging.INFO,  # 定义输出到文件的log级别,大于此级别的都被输出
    format='%(asctime)s  %(filename)s  %(levelname)s : %(message)s',  # 定义输出log的格式
    datefmt='%Y-%m-%d %H:%M:%S',  # 时间
    filename="{}info.log".format(time.strftime('%Y%m%d')),  # log文件名
    filemode='a',  # 写入模式“w”或“a”
)
console = logging.StreamHandler()
console.setLevel(logging.INFO)
# 设置格式
formatter = logging.Formatter('%(asctime)s  %(filename)s  %(levelname)s : %(message)s')
# 告诉handler使用这个格式
console.setFormatter(formatter)
# 为root logger添加handler
logging.getLogger('').addHandler(console)


# 设置日志大小,日志滚动删除
import logging
import logging.handlers

mylog = logging.getLogger()
mylog.setLevel(logging.INFO)
formatter = logging.Formatter('%(levelname)s: %(asctime)s %(filename)s %(message)s')
filehandler = logging.handlers.RotatingFileHandler(
    filename="a.log",
    mode='a',  # # 写入模式“w”或“a”
    maxBytes=10 * 1024 * 1024,  # 1MB重写一个文件
    backupCount=10)  # ,保留2(backupCount) 个旧文件
filehandler.setFormatter(formatter)
logging.getLogger('').addHandler(filehandler)

console = logging.StreamHandler()
console.setLevel(logging.INFO)
# 设置格式
formatter = logging.Formatter('%(asctime)s  %(filename)s  %(levelname)s : %(message)s')
# 告诉handler使用这个格式
console.setFormatter(formatter)
# 为root logger添加handler
logging.getLogger('').addHandler(console) 

6.logging.basicConfig中文输出乱码

# 1.进入logging日志 __init__.py文件

# 2.找到
class FileHandler(StreamHandler):
    """
    A handler class which writes formatted logging records to disk files.
    """
    def __init__(self, filename, mode='a', encoding=None, delay=False):
        """
        Open the specified file and use it as the stream for logging.
        """
        # Issue #27493: add support for Path objects to be passed in
        filename = os.fspath(filename)
        #keep the absolute path, otherwise derived classes which use this
        #may come a cropper when the current directory changes
        self.baseFilename = os.path.abspath(filename)
        self.mode = mode
        self.encoding = encoding
        self.delay = delay
        if delay:
            #We don't open the stream, but we still need to call the
            #Handler constructor to set level, formatter, lock etc.
            Handler.__init__(self)
            self.stream = None
        else:
            StreamHandler.__init__(self, self._open())

# 3.将encoding=None改成  encoding='utf-8'
class FileHandler(StreamHandler):
    """
    A handler class which writes formatted logging records to disk files.
    """
    def __init__(self, filename, mode='a', encoding='utf-8', delay=False):
        """
        Open the specified file and use it as the stream for logging.
        """
        # Issue #27493: add support for Path objects to be passed in
        filename = os.fspath(filename)
        #keep the absolute path, otherwise derived classes which use this
        #may come a cropper when the current directory changes
        self.baseFilename = os.path.abspath(filename)
        self.mode = mode
        self.encoding = encoding
        self.delay = delay
        if delay:
            #We don't open the stream, but we still need to call the
            #Handler constructor to set level, formatter, lock etc.
            Handler.__init__(self)
            self.stream = None
        else:
            StreamHandler.__init__(self, self._open())




h = FileHandler(filename mode) 换成 h = FileHandler(filename.encode("utf-8"), mode)   # log文件pycharm打不开

  

7.多个python使用同一个日志文件

import logging
import os
import sys

path = os.path.dirname(os.path.abspath(__file__))
sys.path.append(path)


class MyLogging(object):
    # 初始化日志
    def __init__(self):
        logging.basicConfig(
            level=logging.DEBUG,  # 定义输出到文件的log级别,大于此级别的都被输出
            format='%(asctime)s  %(filename)s  %(levelname)s : %(message)s',  # 定义输出log的格式
            datefmt='%Y-%m-%d %H:%M:%S',  # 时间
            filename='{}/steam_download.log'.format(path),  # log文件名
            filemode='a')  # 写入模式“w”或“a”
        console = logging.StreamHandler()
        console.setLevel(logging.INFO)
        # 设置格式
        formatter = logging.Formatter('%(asctime)s  %(filename)s  %(levelname)s : %(message)s')
        # 告诉handler使用这个格式
        console.setFormatter(formatter)
        # 为root logger添加handler
        logging.getLogger('').addHandler(console)

    def debug(self, content):
        print(content)
        logging.debug(content)

    def info(self, content):
        logging.info(content)

    def warning(self, content):
        logging.warning(content)

    def error(self, content):
        logging.error(content)

    def critical(self, content):
        logging.critical(content)


if __name__ == "__main__":
    myLogging = MyLogging()
    myLogging.info("fff")

'''
# 其他地方使用这个日志
from common_log import MyLogging
myLogging = MyLogging()
myLogging.info("debug错误")
'''