如何在Python中找到引发异常的位置

Question

如何确定引发了什么函数异常.例如,存在两个函数:'foo'和'bar'.在'foo'中,异常将随机提出.

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" % ???

Answer 1

import inspect

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

Answer 2

我使用回溯模块，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，回溯将告诉错误发生位置的行号和字符号:)

编辑：

为了适应Habibutsu的评论：Yes, it's useful for printing, but when needed to get more info (for example function name) - not suitable

文档页面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']

for 的文档字符串与 fortraceback.extract_stack相同traceback.extract_tb

traceback.extract_tb(traceback[, limit])

返回从回溯对象回溯中提取的最多限制“预处理”堆栈跟踪条目的列表。它对于堆栈跟踪的替代格式很有用。如果省略限制或无，则提取所有条目。“预处理”堆栈跟踪条目是一个四元组（文件名、行号、函数名称、文本），表示通常为堆栈跟踪打印的信息。文本是去除了前导和尾随空格的字符串；如果源不可用，则为 None。