获取导致exception的exception描述和堆栈跟踪，全部为一个string

我在Python中看到了很多关于堆栈跟踪和exception的文章。 但还没有find我所需要的。

我有一大堆的Python 2.7代码，可能会引发exception。 我想抓住它，并分配给一个string的完整描述和导致错误的堆栈跟踪（我们只是用在控制台上看到的）。 我需要这个string将其打印到GUI中的文本框中。

像这样的东西：

try: method_that_can_raise_an_exception(params) except Exception, e: print_to_textbox(complete_exception_description(e)) 

问题是： 函数complete_exception_description是什么？

Answer 1

请参阅traceback模块，特别是format_exc()函数。 这里

 import traceback try: raise ValueError except: tb = traceback.format_exc() else: tb = "No error" finally: print tb 

Answer 2

 >>> import sys >>> import traceback >>> try: ... 5 / 0 ... except ZeroDivisionError, e: ... type_, value_, traceback_ = sys.exc_info() >>> traceback.format_tb(traceback_) [' File "<stdin>", line 2, in <module>\n'] >>> value_ ZeroDivisionError('integer division or modulo by zero',) >>> type_ <type 'exceptions.ZeroDivisionError'> >>> >>> 5 / 0 Traceback (most recent call last): File "<stdin>", line 1, in <module> ZeroDivisionError: integer division or modulo by zero 

您可以使用sys.exc_info（）来收集traceback模块中的信息和函数来对其进行格式化。 这里有一些格式化的例子。

整个exceptionstring在：

 >>> ex = traceback.format_exception(type_, value_, traceback_) >>> ex ['Traceback (most recent call last):\n', ' File "<stdin>", line 2, in <module>\n', 'ZeroDivisionError: integer division or modulo by zero\n'] 

Answer 3

获取导致exception的exception描述和堆栈跟踪，全部为一个string

创build一个相当复杂的stacktrace来certificate我们得到了完整的堆栈跟踪：

 def raise_error(): raise RuntimeError('something bad happened!') def do_something_that_might_error(): raise_error() 

logging完整的堆栈跟踪

最好的做法是为你的模块设置一个logging器。 它将知道模块的名称，并能够更改级别（以及其他属性，例如处理程序）

 import logging logging.basicConfig(level=logging.DEBUG) logger = logging.getLogger(__name__) 

我们可以使用这个logging器来获取错误：

 try: do_something_that_might_error() except Exception as error: logger.exception(error) 

哪些日志：

 ERROR:__main__:something bad happened! Traceback (most recent call last): File "<stdin>", line 2, in <module> File "<stdin>", line 2, in do_something_that_might_error File "<stdin>", line 2, in raise_error RuntimeError: something bad happened! 

所以我们得到与出现错误时相同的输出：

 >>> do_something_that_might_error() Traceback (most recent call last): File "<stdin>", line 1, in <module> File "<stdin>", line 2, in do_something_that_might_error File "<stdin>", line 2, in raise_error RuntimeError: something bad happened! 

只获取string

如果你真的只想要这个string，可以使用traceback.format_exc函数来演示如何在这里loggingstring：

 import traceback try: do_something_that_might_error() except Exception as error: just_the_string = traceback.format_exc() logger.debug(just_the_string) 

哪些日志：

 DEBUG:__main__:Traceback (most recent call last): File "<stdin>", line 2, in <module> File "<stdin>", line 2, in do_something_that_might_error File "<stdin>", line 2, in raise_error RuntimeError: something bad happened! 

Answer 4

您也可以考虑使用内置的Python模块cgitb来获得一些非常好的格式良好的exception信息，包括局部variables值，源代码上下文，函数参数等。

例如对于这个代码…

 import cgitb cgitb.enable(format='text') def func2(a, divisor): return a / divisor def func1(a, b): c = b - 5 return func2(a, c) func1(1, 5) 

我们得到这个exception输出…

 ZeroDivisionError Python 3.4.2: C:\tools\python\python.exe Tue Sep 22 15:29:33 2015 A problem occurred in a Python script. Here is the sequence of function calls leading up to the error, in the order they occurred. c:\TEMP\cgittest2.py in <module>() 7 def func1(a, b): 8 c = b - 5 9 return func2(a, c) 10 11 func1(1, 5) func1 = <function func1> c:\TEMP\cgittest2.py in func1(a=1, b=5) 7 def func1(a, b): 8 c = b - 5 9 return func2(a, c) 10 11 func1(1, 5) global func2 = <function func2> a = 1 c = 0 c:\TEMP\cgittest2.py in func2(a=1, divisor=0) 3 4 def func2(a, divisor): 5 return a / divisor 6 7 def func1(a, b): a = 1 divisor = 0 ZeroDivisionError: division by zero __cause__ = None __class__ = <class 'ZeroDivisionError'> __context__ = None __delattr__ = <method-wrapper '__delattr__' of ZeroDivisionError object> __dict__ = {} __dir__ = <built-in method __dir__ of ZeroDivisionError object> __doc__ = 'Second argument to a division or modulo operation was zero.' __eq__ = <method-wrapper '__eq__' of ZeroDivisionError object> __format__ = <built-in method __format__ of ZeroDivisionError object> __ge__ = <method-wrapper '__ge__' of ZeroDivisionError object> __getattribute__ = <method-wrapper '__getattribute__' of ZeroDivisionError object> __gt__ = <method-wrapper '__gt__' of ZeroDivisionError object> __hash__ = <method-wrapper '__hash__' of ZeroDivisionError object> __init__ = <method-wrapper '__init__' of ZeroDivisionError object> __le__ = <method-wrapper '__le__' of ZeroDivisionError object> __lt__ = <method-wrapper '__lt__' of ZeroDivisionError object> __ne__ = <method-wrapper '__ne__' of ZeroDivisionError object> __new__ = <built-in method __new__ of type object> __reduce__ = <built-in method __reduce__ of ZeroDivisionError object> __reduce_ex__ = <built-in method __reduce_ex__ of ZeroDivisionError object> __repr__ = <method-wrapper '__repr__' of ZeroDivisionError object> __setattr__ = <method-wrapper '__setattr__' of ZeroDivisionError object> __setstate__ = <built-in method __setstate__ of ZeroDivisionError object> __sizeof__ = <built-in method __sizeof__ of ZeroDivisionError object> __str__ = <method-wrapper '__str__' of ZeroDivisionError object> __subclasshook__ = <built-in method __subclasshook__ of type object> __suppress_context__ = False __traceback__ = <traceback object> args = ('division by zero',) with_traceback = <built-in method with_traceback of ZeroDivisionError object> The above is a description of an error in a Python program. Here is the original traceback: Traceback (most recent call last): File "cgittest2.py", line 11, in <module> func1(1, 5) File "cgittest2.py", line 9, in func1 return func2(a, c) File "cgittest2.py", line 5, in func2 return a / divisor ZeroDivisionError: division by zero 

Answer 5

在Python 3中，下面的代码将完全按照使用traceback.format_exc()所获得的格式对Exception对象进行格式化：

 import traceback try: method_that_can_raise_an_exception(params) except Exception as ex: print(''.join(traceback.format_exception(etype=type(ex), value=ex, tb=ex.__traceback__))) 

好处是只需要Exception对象（感谢logging的__traceback__属性），因此可以更容易地将其作为parameter passing给另一个函数以供进一步处理。

Answer 6

对于那些使用Python-3

使用traceback模块和exception.__traceback__可以提取堆栈跟踪如下：

• 使用traceback.extract_stack()获取当前的堆栈跟踪
• 删除最后三个元素（因为这些是在我的debuggingfunction的堆栈中的条目）
• 使用traceback.extract_tb()从exception对象追加__traceback__
• 使用traceback.format_list()格式化整个事物

 import traceback def exception_to_string(excp): stack = traceback.extract_stack()[:-3] + traceback.extract_tb(excp.__traceback__) # add limit=?? pretty = traceback.format_list(stack) return ''.join(pretty) + '\n {} {}'.format(excp.__class__,excp) 

一个简单的示范：

 def foo(): try: something_invalid() except Exception as e: print(exception_to_string(e)) def bar(): return foo() 

当我们调用bar()时，我们得到以下输出：

  File "./test.py", line 57, in <module> bar() File "./test.py", line 55, in bar return foo() File "./test.py", line 50, in foo something_invalid() <class 'NameError'> name 'something_invalid' is not defined 

Answer 7

我的2分钱：

 import sys, traceback try: ... except Exception, e: T, V, TB = sys.exc_info() print ''.join(traceback.format_exception(T,V,TB)) 

Answer 8

我定义了下面的助手类：

 import traceback class TracedExeptions(object): def __init__(self): pass def __enter__(self): pass def __exit__(self, etype, value, tb): if value : if not hasattr(value, 'traceString'): value.traceString = "\n".join(traceback.format_exception(etype, value, tb)) return False return True 

我可以在以后使用这样的：

 with TracedExeptions(): #some-code-which-might-throw-any-exception 

后来可以像这样消耗它：

 def log_err(ex): if hasattr(ex, 'traceString'): print("ERROR:{}".format(ex.traceString)); else: print("ERROR:{}".format(ex)); 

（背景：因为Promise与Exception一起使用Promise所以我很沮丧，不幸的是，它将一个地方引发的Exception传递给另一个地方的on_rejected处理程序，因此很难从原始位置获取回溯）