你应该用t。配置应用程序写入标准输出，并运行

python3 app.py | tee log.txt

然后您将在stdout和log.txt中获得日志消息。

记录文件和stderr的最简单方法:

import logging

logging.basicConfig(filename="logfile.txt")
stderrLogger=logging.StreamHandler()
stderrLogger.setFormatter(logging.Formatter(logging.BASIC_FORMAT))
logging.getLogger().addHandler(stderrLogger)

我简化了我的源代码(其原始版本是OOP并使用配置文件)，为您提供了@EliasStrehle的一个替代解决方案，而不使用dictConfig(因此最容易与现有源代码集成):

import logging
import sys


def create_stream_handler(stream, formatter, level, message_filter=None):
    handler = logging.StreamHandler(stream=stream)
    handler.setLevel(level)
    handler.setFormatter(formatter)
    if message_filter:
        handler.addFilter(message_filter)
    return handler


def configure_logger(logger: logging.Logger, enable_console: bool = True, enable_file: bool = True):
    if not logger.handlers:
        if enable_console:
            message_format: str = '{asctime:20} {name:16} {levelname:8} {message}'
            date_format: str = '%Y/%m/%d %H:%M:%S'
            level: int = logging.DEBUG
            formatter = logging.Formatter(message_format, date_format, '{')

            # Configures error output (from Warning levels).
            error_output_handler = create_stream_handler(sys.stderr, formatter,
                                                         max(level, logging.WARNING))
            logger.addHandler(error_output_handler)

            # Configures standard output (from configured Level, if lower than Warning,
            #  and excluding everything from Warning and higher).
            if level < logging.WARNING:
                standard_output_filter = lambda record: record.levelno < logging.WARNING
                standard_output_handler = create_stream_handler(sys.stdout, formatter, level,
                                                                standard_output_filter)
                logger.addHandler(standard_output_handler)

        if enable_file:
            message_format: str = '{asctime:20} {name:16} {levelname:8} {message}'
            date_format: str = '%Y/%m/%d %H:%M:%S'
            level: int = logging.DEBUG
            output_file: str = '/tmp/so_test.log'

            handler = logging.FileHandler(output_file)
            formatter = logging.Formatter(message_format, date_format, '{')
            handler.setLevel(level)
            handler.setFormatter(formatter)
            logger.addHandler(handler)

这是一个非常简单的测试方法:

logger: logging.Logger = logging.getLogger('MyLogger')
logger.setLevel(logging.DEBUG)
configure_logger(logger, True, True)
logger.debug('Debug message ...')
logger.info('Info message ...')
logger.warning('Warning ...')
logger.error('Error ...')
logger.fatal('Fatal message ...')

下面是一种基于强大但缺乏文档记录的logging.config.dictConfig方法的解决方案。 它不是将每个日志消息发送到stdout，而是将日志级别为ERROR或更高的消息发送到stderr，将其他所有消息发送到stdout。 如果系统的其他部分正在侦听stderr或stdout，这可能很有用。

import logging
import logging.config
import sys

class _ExcludeErrorsFilter(logging.Filter):
    def filter(self, record):
        """Only lets through log messages with log level below ERROR ."""
        return record.levelno < logging.ERROR


config = {
    'version': 1,
    'filters': {
        'exclude_errors': {
            '()': _ExcludeErrorsFilter
        }
    },
    'formatters': {
        # Modify log message format here or replace with your custom formatter class
        'my_formatter': {
            'format': '(%(process)d) %(asctime)s %(name)s (line %(lineno)s) | %(levelname)s %(message)s'
        }
    },
    'handlers': {
        'console_stderr': {
            # Sends log messages with log level ERROR or higher to stderr
            'class': 'logging.StreamHandler',
            'level': 'ERROR',
            'formatter': 'my_formatter',
            'stream': sys.stderr
        },
        'console_stdout': {
            # Sends log messages with log level lower than ERROR to stdout
            'class': 'logging.StreamHandler',
            'level': 'DEBUG',
            'formatter': 'my_formatter',
            'filters': ['exclude_errors'],
            'stream': sys.stdout
        },
        'file': {
            # Sends all log messages to a file
            'class': 'logging.FileHandler',
            'level': 'DEBUG',
            'formatter': 'my_formatter',
            'filename': 'my.log',
            'encoding': 'utf8'
        }
    },
    'root': {
        # In general, this should be kept at 'NOTSET'.
        # Otherwise it would interfere with the log levels set for each handler.
        'level': 'NOTSET',
        'handlers': ['console_stderr', 'console_stdout', 'file']
    },
}

logging.config.dictConfig(config)

您可以为文件和stdout创建两个处理程序，然后创建一个记录器，其中的handlers参数为basicConfig。如果两个处理程序有相同的log_level和format输出，这可能会很有用:

import logging
import sys

file_handler = logging.FileHandler(filename='tmp.log')
stdout_handler = logging.StreamHandler(stream=sys.stdout)
handlers = [file_handler, stdout_handler]

logging.basicConfig(
    level=logging.DEBUG, 
    format='[%(asctime)s] {%(filename)s:%(lineno)d} %(levelname)s - %(message)s',
    handlers=handlers
)

logger = logging.getLogger('LOGGER_NAME')

你应该用t。配置应用程序写入标准输出，并运行

python3 app.py | tee log.txt

然后您将在stdout和log.txt中获得日志消息。