我正在用logging.error将Python异常消息打印到日志文件:

import logging
try:
    1/0
except ZeroDivisionError as e:
    logging.error(e)  # ERROR:root:division by zero

是否可以打印有关异常和生成异常的代码的更详细信息,而不仅仅是异常字符串?行号或堆栈跟踪之类的东西会很棒。


当前回答

一点点装饰处理(非常松散的灵感来自可能单子和提升)。您可以安全地删除Python 3.6类型注释,并使用较旧的消息格式化样式。

fallible.py

from functools import wraps
from typing import Callable, TypeVar, Optional
import logging


A = TypeVar('A')


def fallible(*exceptions, logger=None) \
        -> Callable[[Callable[..., A]], Callable[..., Optional[A]]]:
    """
    :param exceptions: a list of exceptions to catch
    :param logger: pass a custom logger; None means the default logger, 
                   False disables logging altogether.
    """
    def fwrap(f: Callable[..., A]) -> Callable[..., Optional[A]]:

        @wraps(f)
        def wrapped(*args, **kwargs):
            try:
                return f(*args, **kwargs)
            except exceptions:
                message = f'called {f} with *args={args} and **kwargs={kwargs}'
                if logger:
                    logger.exception(message)
                if logger is None:
                    logging.exception(message)
                return None

        return wrapped

    return fwrap

演示:

In [1] from fallible import fallible

In [2]: @fallible(ArithmeticError)
    ...: def div(a, b):
    ...:     return a / b
    ...: 
    ...: 

In [3]: div(1, 2)
Out[3]: 0.5

In [4]: res = div(1, 0)
ERROR:root:called <function div at 0x10d3c6ae8> with *args=(1, 0) and **kwargs={}
Traceback (most recent call last):
  File "/Users/user/fallible.py", line 17, in wrapped
    return f(*args, **kwargs)
  File "<ipython-input-17-e056bd886b5c>", line 3, in div
    return a / b

In [5]: repr(res)
'None'

您还可以修改这个解决方案,从except部分返回比None更有意义的内容(甚至可以通过在fallible的参数中指定这个返回值,使解决方案具有泛型)。

其他回答

您可以记录堆栈跟踪而不出现异常。

https://docs.python.org/3/library/logging.html#logging.Logger.debug

The second optional keyword argument is stack_info, which defaults to False. If true, stack information is added to the logging message, including the actual logging call. Note that this is not the same stack information as that displayed through specifying exc_info: The former is stack frames from the bottom of the stack up to the logging call in the current thread, whereas the latter is information about stack frames which have been unwound, following an exception, while searching for exception handlers.

例子:

>>> import logging
>>> logging.basicConfig(level=logging.DEBUG)
>>> logging.getLogger().info('This prints the stack', stack_info=True)
INFO:root:This prints the stack
Stack (most recent call last):
  File "<stdin>", line 1, in <module>
>>>

如果你看一下这个代码示例(适用于Python 2和3),你会看到下面可以提取的函数定义

方法 行号 代码的上下文 文件路径

对于整个堆栈跟踪,无论是否有异常:

def sentry_friendly_trace(get_last_exception=True):
    try:
        current_call = list(map(frame_trans, traceback.extract_stack()))
        alert_frame = current_call[-4]
        before_call = current_call[:-4]

        err_type, err, tb = sys.exc_info() if get_last_exception else (None, None, None)
        after_call = [alert_frame] if err_type is None else extract_all_sentry_frames_from_exception(tb)

        return before_call + after_call, err, alert_frame
    except:
        return None, None, None

当然,这个函数依赖于上面链接的整个要点,特别是extract_all_sentry_frames_from_exception()和frame_trans(),但是异常信息提取总共不到60行。

希望有帮助!

引用

如果您的应用程序以其他方式记录日志-不使用日志模块?

现在,traceback可以用在这里。

import traceback

def log_traceback(ex, ex_traceback=None):
    if ex_traceback is None:
        ex_traceback = ex.__traceback__
    tb_lines = [ line.rstrip('\n') for line in
                 traceback.format_exception(ex.__class__, ex, ex_traceback)]
    exception_logger.log(tb_lines)

在Python 2中使用它: 试一试: #你的函数调用在这里 Exception as ex: _, _, ex_traceback = sys.exc_info() ex_traceback log_traceback(例) 在Python 3中使用它: 试一试: X = get_number() Exception as ex: log_traceback(特异)

我把所有的函数都包在我的自定义设计的日志记录器周围:

import json
import timeit
import traceback
import sys
import unidecode

def main_writer(f,argument):
  try:
    f.write(str(argument))
  except UnicodeEncodeError:
    f.write(unidecode.unidecode(argument))


def logger(*argv,logfile="log.txt",singleLine = False):
  """
  Writes Logs to LogFile
  """
  with open(logfile, 'a+') as f:
    for arg in argv:
      if arg == "{}":
        continue
      if type(arg) == dict and len(arg)!=0:
        json_object = json.dumps(arg, indent=4, default=str)
        f.write(str(json_object))
        f.flush()
        """
        for key,val in arg.items():
          f.write(str(key) + " : "+ str(val))
          f.flush()
        """
      elif type(arg) == list and len(arg)!=0:
        for each in arg:
          main_writer(f,each)
          f.write("\n")
          f.flush()
      else:
        main_writer(f,arg)
        f.flush()
      if singleLine==False:
        f.write("\n")
    if singleLine==True:
      f.write("\n")

def tryFunc(func, func_name=None, *args, **kwargs):
  """
  Time for Successfull Runs
  Exception Traceback for Unsuccessful Runs
  """
  stack = traceback.extract_stack()
  filename, codeline, funcName, text = stack[-2]
  func_name = func.__name__ if func_name is None else func_name # sys._getframe().f_code.co_name # func.__name__
  start = timeit.default_timer()
  x = None
  try:
    x = func(*args, **kwargs)
    stop = timeit.default_timer()
    # logger("Time to Run {} : {}".format(func_name, stop - start))
  except Exception as e:
    logger("Exception Occurred for {} :".format(func_name))
    logger("Basic Error Info :",e)
    logger("Full Error TraceBack :")
    # logger(e.message, e.args)
    logger(traceback.format_exc())
  return x

def bad_func():
  return 'a'+ 7

if __name__ == '__main__':
    logger(234)
    logger([1,2,3])
    logger(['a','b','c'])
    logger({'a':7,'b':8,'c':9})
    tryFunc(bad_func)

在日志模块(如果是自定义模块)中启用stack_info。

api_logger.exceptionLog("*Input your Custom error message*",stack_info=True)