如何在Python中找到引发异常的位置

时间:2014-03-06 17:51:31

标签: python exception

如何确定引发的异常函数。例如,存在两个函数:'foo'和'bar'。在'foo'中,异常会随机出现。

import random


def foo():
    if random.randint(1, 10) % 2:
        raise Exception
    bar()


def bar():
    raise Exception

try:
    foo()
except Exception as e:
    print "Exception raised in %s" % ???

3 个答案:

答案 0 :(得分:6)

import inspect

try:
    foo()
except Exception as e:
    print "Exception raised in %s" % inspect.trace()[-1][3]

答案 1 :(得分:3)

我使用跟踪模块,如下所示:

import traceback

try:
    1 / 0
except Exception:
    print traceback.format_exc()

这给出了以下输出:

Traceback (most recent call last):
  File "<ipython-input-3-6b05b5b621cb>", line 2, in <module>
    1 / 0
ZeroDivisionError: integer division or modulo by zero

如果代码从文件运行,则回溯将告诉错误发生的位置的行和字符数:)

修改

以适应HabibutsuYes, it's useful for printing, but when needed to get more info (for example function name) - not suitable

的评论

doc-pages告诉您如何以编程方式提取跟踪:http://docs.python.org/2/library/traceback.html

从上面链接的页面:

>>> import traceback
>>> def another_function():
...     lumberstack()
...
>>> def lumberstack():
...     traceback.print_stack()
...     print repr(traceback.extract_stack())
...     print repr(traceback.format_stack())
...
>>> another_function()
  File "<doctest>", line 10, in <module>
    another_function()
  File "<doctest>", line 3, in another_function
    lumberstack()
  File "<doctest>", line 6, in lumberstack
    traceback.print_stack()
[('<doctest>', 10, '<module>', 'another_function()'),
 ('<doctest>', 3, 'another_function', 'lumberstack()'),
 ('<doctest>', 7, 'lumberstack', 'print repr(traceback.extract_stack())')]
['  File "<doctest>", line 10, in <module>\n    another_function()\n',
 '  File "<doctest>", line 3, in another_function\n    lumberstack()\n',
 '  File "<doctest>", line 8, in lumberstack\n    print repr(traceback.format_stack())\n']

traceback.extract_stack的文档字符串与traceback.extract_tb

的文档字符串相同
  

traceback.extract_tb(traceback [,limit])

     

返回最多限制“预处理”堆栈跟踪条目的列表   从traceback对象traceback中提取。它很有用   堆栈跟踪的替代格式。如果省略limit或None,则全部   提取条目。 “预处理”堆栈跟踪条目是a   四倍(文件名,行号,函数名,文本)代表   通常为堆栈跟踪打印的信息。文字是   剥离前导和尾随空格的字符串;如果来源   不可用它是无。

答案 2 :(得分:2)

你的目标是什么?如果您担心barfoo抛出相同的异常类型且调用者无法区分它们,只需派生一个新的异常类:

import random

class FooException(Exception):
    """An exception thrown only by foo."""

def foo():
    if random.randint(1,10) % 2:
        raise FooException

    bar()

def bar():
    raise Exception

try:
    foo()
except FooException:
    print "Exception raised in foo..."
except:
    print "Exception raised in bar (probably)..."