我想将所有中间日志消息(警告,信息,错误)存储到python中的字符串,最后在程序结束时,将所有内容显示为控制台的报告。
我尝试按照中列出的步骤进行操作 http://opensourcehacker.com/2011/02/23/temporarily-capturing-python-logging-output-to-a-string-buffer/ 但没有成功。
有人能告诉我一个简短,干净的方法吗?
这就是我现在所尝试的:
log = logging.getLogger('basic_logger')
log.setLevel(logging.DEBUG)
report=""
memory_handler=logging.handlers.MemoryHandler(1024*20,logging.ERROR,report)
memory_handler.setLevel(logging.DEBUG)
log.addHandler(memory_handler)
log.info("hello world")
memory_handler.flush()
print "report:",report
答案 0 :(得分:12)
它可以像记录到StringIO
对象一样简单:
import logging
try:
from cStringIO import StringIO # Python 2
except ImportError:
from io import StringIO
log_stream = StringIO()
logging.basicConfig(stream=log_stream, level=logging.INFO)
logging.info('hello world')
logging.warning('be careful!')
logging.debug("you won't see this")
logging.error('you will see this')
logging.critical('critical is logged too!')
print(log_stream.getvalue())
<强>输出强>
INFO:root:hello world WARNING:root:be careful! ERROR:root:you will see this CRITICAL:root:critical is logged too!
如果您只想记录WARN,INFO和ERROR级别的消息,可以使用过滤器。下面LevelFilter
检查每个日志记录的级别号,只允许那些所需级别的记录:
import logging
try:
from cStringIO import StringIO # Python 2
except ImportError:
from io import StringIO
class LevelFilter(logging.Filter):
def __init__(self, levels):
self.levels = levels
def filter(self, record):
return record.levelno in self.levels
log_stream = StringIO()
logging.basicConfig(stream=log_stream, level=logging.NOTSET)
logging.getLogger().addFilter(LevelFilter((logging.INFO, logging.WARNING, logging.ERROR)))
logging.info('hello world')
logging.warning('be careful!')
logging.debug("you won't see this")
logging.error('you will see this')
logging.critical('critical is no longer logged!')
print(log_stream.getvalue())
<强>输出强>
INFO:root:hello world WARNING:root:be careful! ERROR:root:you will see this
答案 1 :(得分:1)
您也可以编写自己的流类。正如https://docs.python.org/2/library/logging.handlers.html所述,只有write
和flush
用于流媒体。
示例:强>
import logging
class LogStream(object):
def __init__(self):
self.logs = ''
def write(self, str):
self.logs += str
def flush(self):
pass
def __str__(self):
return self.logs
log_stream = LogStream()
logging.basicConfig(stream=log_stream, level=logging.DEBUG)
log = logging.getLogger('test')
log.debug('debugging something')
log.info('informing user')
print(log_stream)
<强>输出:强>
DEBUG:test:debugging something
INFO:test:informing user
答案 2 :(得分:1)
请注意,涉及basicConfig
的解决方案设置了所有其他记录器都继承的 root 记录器的属性,这是不必要的,因为库也将记录到该属性。我的用例是一个调用数据处理模块的网站,我只想专门捕获该模块的日志。这还具有允许登录到文件的现有处理程序和终端保留的优点:
import io, logging
from django.http import HttpResponse
log_stream = io.StringIO()
log_handler = logging.StreamHandler(log_stream)
logging.getLogger('algorithm.user_output').addHandler(log_handler)
algorithm()
return HttpResponse(f'<pre>{log_stream.getvalue()}</pre>')
在algorithm.py
中:
logger = logging.getLogger(__name__ + '.user_output') # 'algorithm.user_output'
答案 3 :(得分:0)
注意:
这是@mhawke Answer 的定制版本---> HERE 我需要有多个日志让每个日志都做它的事情,这是一个简单的脚本。
from io import StringIO
from datetime import date
# Formatter
LOG_FORMAT = '| %(asctime)s | %(name)s-%(levelname)s: %(message)s '
FORMATTER = logging.Formatter(LOG_FORMAT)
# ------- MAIN LOGGER
main_handler = logging.StreamHandler()
main_handler.setLevel(logging.WARNING)
main_handler.setFormatter(FORMATTER)
# ------- FILE LOGGER
file_handler = logging.FileHandler(f'log_{date.strftime(date.today(), "%Y-%m-%d")}.log')
file_handler.setLevel(logging.INFO)
file_handler.setFormatter(FORMATTER)
# ------- SECONDARY STREAMER (HOLDS ALL THE LOGS FOR RETRIEVE LATER) LOGGER
streamer = StringIO()
stream_handler = logging.StreamHandler(stream=streamer)
stream_handler.setFormatter(FORMATTER)
# Root Logger
logging.basicConfig(level=10, handlers=[main_handler, file_handler, stream_handler]) # Add handlers to Logger
_logger = logging.getLogger(__name__)
_logger.log(10, "DEBUG MESSAGE")
_logger.log(20, "INFO MESSAGE")
_logger.log(30, "WARNING MESSAGE")
_logger.log(40, "ERROR!")
_logger.log(50, "CRITICAL")
print('==='*15)
print('\nGetting All logs from StringIO')
print(streamer.getvalue())
此外,我需要再次从 0 开始清除数据。最简单且性能更快的方法是创建一个新的 StringIO 实例并将其附加到 StreamHandler 实例。
new_streamer = StringIO() # Creating the new instance
stream_handler.setStream(new_streamer) # here we assign it to the logger
_logger.info("New Message")
_logger.info("New Message")
_logger.info("New Message")
print(new_streamer.getvalue()) # New data
另一种方法是“清除”流,但根据 @Chris Morgan 的其他 **StackOverflow Answer 性能较低。
# Python 3
streamer.truncate(0)
streamer.seek(0)
_logger.info("New Message")
_logger.info("New Message")
_logger.info("New Message")
print(streamer.getvalue())
# Python 2
streamer.truncate(0)
_logger.info("New Message")
_logger.info("New Message")
_logger.info("New Message")
print(streamer.getvalue())
答案 4 :(得分:-1)
也许这个示例代码就足够了
通常,您应该发布您的代码,以便我们可以看到正在发生的事情。
在阅读任何给定的教程时,您还应该查看日志记录模块的实际Python文档
https://docs.python.org/2/library/logging.html
标准Python日志记录模块可以登录到文件。完成日志记录后,可以将该文件的内容打印到shell输出中。
# Do some logging to a file
fname = 'mylog.log'
logging.basicConfig(filename=fname, level=logging.INFO)
logging.info('Started')
logging.info('Finished')
# Print the output
with open(fname, 'r') as f:
print f.read() # You could also store f.read() to a string