我已经处理了将日志和打印同时重定向到磁盘、stdout和stderr上的文件，通过以下模块(Gist也可以在这里找到):

import logging
import pathlib
import sys

from ml.common.const import LOG_DIR_PATH, ML_DIR


def create_log_file_path(file_path, root_dir=ML_DIR, log_dir=LOG_DIR_PATH):
    path_parts = list(pathlib.Path(file_path).parts)
    relative_path_parts = path_parts[path_parts.index(root_dir) + 1:]
    log_file_path = pathlib.Path(log_dir, *relative_path_parts)
    log_file_path = log_file_path.with_suffix('.log')
    # Create the directories and the file itself
    log_file_path.parent.mkdir(parents=True, exist_ok=True)
    log_file_path.touch(exist_ok=True)
    return log_file_path


def set_up_logs(file_path, mode='a', level=logging.INFO):
    log_file_path = create_log_file_path(file_path)
    logging_handlers = [logging.FileHandler(log_file_path, mode=mode),
                        logging.StreamHandler(sys.stdout)]
    logging.basicConfig(
        handlers=logging_handlers,
        format='%(asctime)s %(name)s %(levelname)s %(message)s',
        level=level
    )


class OpenedFileHandler(logging.FileHandler):

    def __init__(self, file_handle, filename, mode):
        self.file_handle = file_handle
        super(OpenedFileHandler, self).__init__(filename, mode)

    def _open(self):
        return self.file_handle


class StandardError:
    def __init__(self, buffer_stderr, buffer_file):
        self.buffer_stderr = buffer_stderr
        self.buffer_file = buffer_file

    def write(self, message):
        self.buffer_stderr.write(message)
        self.buffer_file.write(message)


class StandardOutput:
    def __init__(self, buffer_stdout, buffer_file):
        self.buffer_stdout = buffer_stdout
        self.buffer_file = buffer_file

    def write(self, message):
        self.buffer_stdout.write(message)
        self.buffer_file.write(message)


class Logger:
    def __init__(self, file_path, mode='a', level=logging.INFO):
        self.stdout_ = sys.stdout
        self.stderr_ = sys.stderr

        log_file_path = create_log_file_path(file_path)
        self.file_ = open(log_file_path, mode=mode)

        logging_handlers = [OpenedFileHandler(self.file_, log_file_path,
                                              mode=mode),
                            logging.StreamHandler(sys.stdout)]
        logging.basicConfig(
            handlers=logging_handlers,
            format='%(asctime)s %(name)s %(levelname)s %(message)s',
            level=level
        )

    # Overrides write() method of stdout and stderr buffers
    def write(self, message):
        self.stdout_.write(message)
        self.stderr_.write(message)
        self.file_.write(message)

    def flush(self):
        pass

    def __enter__(self):
        sys.stdout = StandardOutput(self.stdout_, self.file_)
        sys.stderr = StandardError(self.stderr_, self.file_)

    def __exit__(self, exc_type, exc_val, exc_tb):
        sys.stdout = self.stdout_
        sys.stderr = self.stderr_
        self.file_.close()

作为上下文管理器编写，您可以通过添加额外的一行来简单地将功能添加到您的python脚本:

from logger import Logger

...

if __name__ == '__main__':
    with Logger(__file__):
        main()

添加不带参数的StreamHandler将使用stderr而不是stdout。如果其他进程依赖于stdout转储(例如，在编写NRPE插件时)，那么请确保显式指定stdout，否则您可能会遇到一些意想不到的麻烦。

下面是一个快速示例，重用问题中的假设值和LOGFILE:

import logging
from logging.handlers import RotatingFileHandler
from logging import handlers
import sys

log = logging.getLogger('')
log.setLevel(logging.DEBUG)
format = logging.Formatter("%(asctime)s - %(name)s - %(levelname)s - %(message)s")

ch = logging.StreamHandler(sys.stdout)
ch.setFormatter(format)
log.addHandler(ch)

fh = handlers.RotatingFileHandler(LOGFILE, maxBytes=(1048576*5), backupCount=7)
fh.setFormatter(format)
log.addHandler(fh)

在多个Python包中反复使用Waterboy的代码后，我最终将其转换为一个独立的小Python包，你可以在这里找到:

https://github.com/acschaefer/duallog

该代码有良好的文档，易于使用。只需下载.py文件并将其包含在您的项目中，或通过pip install duallog安装整个包。

只需获得根记录器的句柄并添加StreamHandler。StreamHandler写入stderr。不确定你是否真的需要stdout而不是stderr，但这是我在设置Python日志记录器时使用的，我也添加了FileHandler。然后我所有的日志都去了这两个地方(这听起来像是你想要的)。

import logging
logging.getLogger().addHandler(logging.StreamHandler())

如果希望输出到stdout而不是stderr，只需将其指定给StreamHandler构造函数。

import sys
# ...
logging.getLogger().addHandler(logging.StreamHandler(sys.stdout))

您还可以向它添加一个Formatter，以便所有日志行都有一个公共标题。

ie:

import logging
logFormatter = logging.Formatter("%(asctime)s [%(threadName)-12.12s] [%(levelname)-5.5s]  %(message)s")
rootLogger = logging.getLogger()

fileHandler = logging.FileHandler("{0}/{1}.log".format(logPath, fileName))
fileHandler.setFormatter(logFormatter)
rootLogger.addHandler(fileHandler)

consoleHandler = logging.StreamHandler()
consoleHandler.setFormatter(logFormatter)
rootLogger.addHandler(consoleHandler)

打印格式为:

2012-12-05 16:58:26,618 [MainThread  ] [INFO ]  my message

对于2.7，尝试以下操作:

fh = logging.handlers.RotatingFileHandler(LOGFILE, maxBytes=(1048576*5), backupCount=7)

记录到标准输出和旋转文件的不同级别和格式:

import logging
import logging.handlers
import sys

if __name__ == "__main__":

    # Change root logger level from WARNING (default) to NOTSET in order for all messages to be delegated.
    logging.getLogger().setLevel(logging.NOTSET)

    # Add stdout handler, with level INFO
    console = logging.StreamHandler(sys.stdout)
    console.setLevel(logging.INFO)
    formater = logging.Formatter('%(name)-13s: %(levelname)-8s %(message)s')
    console.setFormatter(formater)
    logging.getLogger().addHandler(console)

    # Add file rotating handler, with level DEBUG
    rotatingHandler = logging.handlers.RotatingFileHandler(filename='rotating.log', maxBytes=1000, backupCount=5)
    rotatingHandler.setLevel(logging.DEBUG)
    formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
    rotatingHandler.setFormatter(formatter)
    logging.getLogger().addHandler(rotatingHandler)

    log = logging.getLogger("app." + __name__)

    log.debug('Debug message, should only appear in the file.')
    log.info('Info message, should appear in file and stdout.')
    log.warning('Warning message, should appear in file and stdout.')
    log.error('Error message, should appear in file and stdout.')