python logging模块日志分析与打印日志
logging.basicConfig(**kwargs):创建默认处理器从而将调试消息写至文件,它接受一个字典
filename:指定文件名,把记录输出定向的文件里面,如果不指定文件名就会直接打印到屏幕上
filemode:指打开文件的模式(默认为a)
format:指定的字符串格式
datefmt:指定日期格式
level:指定日志的级别
级别 值 含义
CRITICAL,FATAL 50 临界
ERROR 40 错误
WARNING,WARN 30 警告
INFO 20 通知
DEBUG 10 调试
代码:
复制代码 代码示例:
#coding:utf-8
import logging
logging.basicConfig(level = logging.INFO)#定义日志级别为INFO级别
#下面是定义各个级别的日志输出
logging.debug('I am debug')
logging.info('I am info')
logging.warn('I am warning')
logging.error('I am error')
logging.critical('I am critical')
######运行结果######
>>> INFO:root:I am info
WARNING:root:I am warning
ERROR:root:I am error
CRITICAL:root:I am critical
由于定义的日志级别是INFO,而debug级别的值只有10,而INFO的是20。
所有不会打印出来,只打印大于INFO值的日志记录,一般调试程序都是直接打印在屏幕,没输出到文件。
logging模块还支持将线程名嵌入到各个日志消息中,利用logging模块调试多线程的例子:
代码:
复制代码 代码示例:
#coding:utf-8
import threading
import time
import logging
logging.basicConfig(level = logging.DEBUG,
format ='[%(levelname)8s]t (%(threadName)10s)t %(message)30s')
def worker():
#logging的日志格式必须是字符型,不接受float和int
logging.debug('worker start:%s'%time.time())
time.sleep(2)
logging.debug('worker done:%s'%time.time())
def saihi():
logging.debug('saihi start:%s'%time.time())
time.sleep(2)
worker()
logging.debug('saihi done:%s'%time.time())
t = threading.Thread(target = saihi, name = 't')
x = threading.Thread(target = worker, name = 'x')
w = threading.Thread(target = worker)
t.start()
x.start()
w.start()
运行结果:
[ DEBUG] ( t) saihi start:1374939516.13
[ DEBUG] ( x) worker start:1374939516.13
[ DEBUG] ( Thread-1) worker start:1374939516.13
[ DEBUG] ( t) worker start:1374939518.13
[ DEBUG] ( Thread-1) worker done:1374939518.13
[ DEBUG] ( x) worker done:1374939518.13
[ DEBUG] ( t) worker done:1374939520.13
[ DEBUG] ( t) saihi done:1374939520.13