从异常对象中提取完整跟踪

Question

我关注this answer并实现了以下内容：

def B():
    try:
        raise Exception()
    except Exception as e:
        traceback_ob = e.__traceback__

        import traceback
        traceback_str = ''.join(traceback.format_exception(etype=type(e), value=e, tb=traceback_ob))

        print(traceback_str)

def A():
    B()

A()

输出是：

Traceback (most recent call last):
  File "/path/bespoke_traceback.py", line 3, in B
    raise Exception()
Exception

我需要完整的跟踪，所以在字符串中包含 A - 我怎样才能做到这一点？

具体来说——我需要这个字符串，而不仅仅是打印出来的。

Answer 1

你可以简单地使用日志模块来实现回溯，不需要其他模块：

对于同一个文件，异常回溯将来自直接类。如果是从不同文件调用，logger.exception 将打印整个回溯

查看以下示例：

import logging
logger = logging.getLogger(__name__)
def B():
    try:
        raise Exception()
    except Exception as e:
        logger.exception("Error",stack_info=True)

def A():
    B()

A()

Answer 2

我的个人方法：（很抱歉使用文件，但它似乎是唯一的解决方案） 有点复杂，抱歉

from threading import Thread
import sys
import os

def B():
    raise Exception()
    
def A():
    B()

def catch_error(f):
    # redirect stderr (where errors are printed) to a temporary file
    # tried StringIO but it only showed part of the exception
    sys.stderr = open('temp', 'w')

    # run it in a thread so that the script doesn't stop after the error
    t = Thread(target=A) 
    t.start()
    t.join()

    # close the file and return stderr back to normal
    sys.stderr.close()
    sys.stderr = sys.__stderr__

    # get error string from the file and then delete it
    s = open('temp', 'r').read()
    os.remove('temp')

    # remove some lines concerning the threading module
    lines = s.split('\n')
    [lines.pop(2) for i in range(4)]
    lines.pop(0)

    # join the lines and return
    return '\n'.join(lines)

print(catch_error(A))

输出：

Traceback (most recent call last):
  File "C:\Users\lenovo\Amin\Workspace\test.py", line 9, in A
    B()
  File "C:\Users\lenovo\Amin\Workspace\test.py", line 6, in B
    raise Exception()
Exception

Answer 3

您可以将format_exception 函数与format_stack 组合起来获取之前的帧：

import traceback

def B():
    try:
        raise Exception("error")
    except Exception as e:
        exception = traceback.format_exception(etype=type(e), value=e, tb=e.__traceback__)
        stack = traceback.format_stack()

        # exception already holds the last (current) frame - we just want to add the previous frames
        exception[1:1] = stack[:-1]

        traceback_str = ''.join(exception)
        print(traceback_str)

def A():
    B()

A()

将给予：

Traceback (most recent call last):
  File "test.py", line 16, in <module>
    A()
  File "test.py", line 14, in A
    B()
  File "test.py", line 5, in B
    raise Exception("error")
Exception: error