Question

我在Python中看到了针对进度条的不同解决方案，但简单的stdout解决方案对我的项目不起作用。我有多个类并使用“logging”模块将信息输出到STDOUT。我有一个功能，我想在一行显示进度条，每次刷新缓冲区。

简单进展的例子：

for i in range(100):
    time.sleep(1)
    sys.stdout.write("\r%d%%" %i)
    sys.stdout.flush()

当我尝试通过STDOUT写入然后刷新缓冲区时，缓冲区未刷新或进度无法进行。我希望避免某种线程或复杂的过程来实现这一点。有人有一种优先的方法来实现这一目标吗？

Answer 1

我无法为此找到一个好的解决方案，所以我写了enlighten progress bar来处理它。基本上它会更改终端的滚动区域，因此日志记录在进度条上方完成，而不是每次要写入STDOUT时都必须重绘进度条。这使您可以根据需要随时写入终端，而无需修改logging，print等。

import logging
import time
import enlighten

# Setup logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger()

# Setup progress bar
manager = enlighten.get_manager()
pbar = manager.counter(total=100, desc='Ticks', unit='ticks')

for i in range(1, 101):
    logger.info("Processing step %s" % i)
    time.sleep(.2)
    pbar.update()

Answer 2

我解决了这个问题：

import logging
import time
from tqdm import tqdm
import io

class TqdmToLogger(io.StringIO):
    """
        Output stream for TQDM which will output to logger module instead of
        the StdOut.
    """
    logger = None
    level = None
    buf = ''
    def __init__(self,logger,level=None):
        super(TqdmToLogger, self).__init__()
        self.logger = logger
        self.level = level or logging.INFO
    def write(self,buf):
        self.buf = buf.strip('\r\n\t ')
    def flush(self):
        self.logger.log(self.level, self.buf)

if __name__ == "__main__":
    logging.basicConfig(format='%(asctime)s [%(levelname)-8s] %(message)s')
    logger = logging.getLogger()
    logger.setLevel(logging.DEBUG)

    tqdm_out = TqdmToLogger(logger,level=logging.INFO)
    for x in tqdm(range(100),file=tqdm_out,mininterval=30,):
        time.sleep(.5)

输出

2016-12-19 15:35:06 [INFO    ] 16%|#####9                                | 768/4928 [07:04<40:50,  1.70it/s]
2016-12-19 15:36:07 [INFO    ] 18%|######6                               | 865/4928 [08:04<40:34,  1.67it/s]

Answer 3

您可以将tqdm progress bar与a custom handler through logging as described here：

一起使用

import logging
import time
import colorlog
from tqdm import tqdm

class TqdmHandler(logging.StreamHandler):
    def __init__(self):
        logging.StreamHandler.__init__(self)

    def emit(self, record):
        msg = self.format(record)
        tqdm.write(msg)

if __name__ == "__main__":
    for x in tqdm(range(100)):
        logger = colorlog.getLogger("MYAPP")
        logger.setLevel(logging.DEBUG)
        handler = TqdmHandler()
        handler.setFormatter(colorlog.ColoredFormatter(
            '%(log_color)s%(name)s | %(asctime)s | %(levelname)s | %(message)s',
            datefmt='%Y-%d-%d %H:%M:%S',
            log_colors={
                'DEBUG': 'cyan',
                'INFO': 'white',
                'SUCCESS:': 'green',
                'WARNING': 'yellow',
                'ERROR': 'red',
                'CRITICAL': 'red,bg_white'},))

        logger.addHandler(handler)
        logger.debug("Inside subtask: "+str(x))
        time.sleep(.5)

Answer 4

如果知道，进度条总是要写入STDOUT，您应该只使用print而不是记录器。请参阅文档in the Python logging tutorial documentation

Answer 5

清理这些提案的代码，这是 IMO 的正确实现，除了 tqdm（也发布 here）外没有任何外部依赖：

import logging
from tqdm import tqdm


class TqdmLoggingHandler(logging.StreamHandler):
    """Avoid tqdm progress bar interruption by logger's output to console"""
    # see logging.StreamHandler.eval method:
    # https://github.com/python/cpython/blob/d2e2534751fd675c4d5d3adc208bf4fc984da7bf/Lib/logging/__init__.py#L1082-L1091
    # and tqdm.write method:
    # https://github.com/tqdm/tqdm/blob/f86104a1f30c38e6f80bfd8fb16d5fcde1e7749f/tqdm/std.py#L614-L620

    def emit(self, record):
        try:
            msg = self.format(record)
            tqdm.write(msg, end=self.terminator)
        except RecursionError:
            raise
        except Exception:
            self.handleError(record)

测试：

import time

log = logging.getLogger(__name__)
log.setLevel(logging.INFO)
log.addHandler(TqdmLoggingHandler())
#   ^-- Assumes this will be the unique handler emitting messages to sys.stdout.
#       If other handlers output to sys.stdout (without tqdm.write),
#       progress bar will be interrupted by those outputs

for i in tqdm(range(20)):
    log.info(f"Looping {i}")
    time.sleep(0.1)

Python进度条通过记录模块

5 个答案: