Python 如何在不停止退出程序的情况下捕获并打印完整的异常回溯

其他一些答案已经指出了traceback模块.

请注意，有了print_exc，在某些情况下，你将无法获得你所期望的.在Python 2中.x:

import traceback

try:
    raise TypeError("Oups!")
except Exception, err:
    try:
        raise TypeError("Again !?!")
    except:
        pass

    traceback.print_exc()

...将显示last异常的回溯:

Traceback (most recent call last):
  File "e.py", line 7, in <module>
    raise TypeError("Again !?!")
TypeError: Again !?!

If you really need to access the original traceback一种解决方案是将从exc_info返回的exception infos缓存在局部变量中，并使用print_exception显示它:

import traceback
import sys

try:
    raise TypeError("Oups!")
except Exception, err:
    try:
        exc_info = sys.exc_info()

        # do you usefull stuff here
        # (potentially raising an exception)
        try:
            raise TypeError("Again !?!")
        except:
            pass
        # end of useful stuff


    finally:
        # Display the *original* exception
        traceback.print_exception(*exc_info)
        del exc_info

制作:

Traceback (most recent call last):
  File "t.py", line 6, in <module>
    raise TypeError("Oups!")
TypeError: Oups!

不过，这方面几乎没有什么缺陷:

• 从sys_info号文件:

  将回溯返回值赋给处理异常的函数中的局部变量将导致circular reference.这将防止同一函数中的局部变量或回溯引用的任何内容被垃圾收集.[...] If you do need the traceback, make sure to delete it after use(最好用try…finally语句)

• 但是，出自同一份文件:

  Beginning with Python 2.2, such cycles are automatically reclaimed当垃圾收集被启用时，它们变得不可访问，但避免创建循环仍然更有效.

另一方面，通过允许您在异常情况下访问回溯associated with，Python3产生了一个不那么令人惊讶的结果:

import traceback

try:
    raise TypeError("Oups!")
except Exception as err:
    try:
        raise TypeError("Again !?!")
    except:
        pass

    traceback.print_tb(err.__traceback__)

...将显示:

  File "e3.py", line 4, in <module>
    raise TypeError("Oups!")