Python 捕捉traceback异常栈信息

相关函数简介

sys.exc_info()

返回包含3个元素(type, value, traceback)的元组，提供关于当前正被处理的异常信息。如果异常没有被处理，返回包含3个None值的元组。

type：存放异常类型(类对象);

Value：获取异常参数(关联的值，或者需要抛出的第二个参数--总是异常类型是个类对象，那该参数总是一个异常类实例)（its associated value or the second argument to raise, which is always a class instance if the exception type is a class object)；

traceback：获取traceback对象，记录异常发生点(根源)。

注意：把traceback值赋值给正在处理当前异常的函数中的本地变量，会引发循环引用问题，会影响垃圾回收。用完后需要删除。

参考连接：

https://docs.python.org/2/library/sys.html#sys.exc_info

traceback.extract_stack()

从stack frame提取原始的traceback

参考连接：

https://hg.python.org/cpython/file/8dffb76faacc/Lib/traceback.py#l280

代码演示

#!/usr/bin/env python

# -*- coding:utf-8 -*-

__author__ = 'shouke'

import sys

import traceback

def testfn():

# 定义异常信息模版

traceback_template = '''Traceback (most recent call last):

File "%(filename)s", line %(lineno)s, in %(name)s

%(type)s: %(message)s\n'''

try:

var = 5

assert var >0, 'var is larger than zero'

assert var % 2 == 0, 'var is not an even number'

except AssertionError:

exc_type, exc_value, exc_traceback = sys.exc_info()

print('异常类型：', exc_type)

print('关联的值，或者需要raise的第二个参数：', exc_value)

print('异常发生点(根源)：', exc_traceback)

print('--------------------------')

traceback_details = {

'filename': exc_traceback.tb_frame.f_code.co_filename, #文件名

'lineno' : exc_traceback.tb_lineno, # 发生异常的行数

'name' : exc_traceback.tb_frame.f_code.co_name, # 所在函数

'type' : exc_type.__name__, # 异常类型

'message' : exc_value

}

traceback_info = traceback_template % traceback_details

print(traceback_info)

print('--------------------------')

raw_traceback = traceback.extract_stack()

print(raw_traceback)

finally: # 为避免垃圾回收问题需要删除

del (exc_type, exc_value, exc_traceback)

testfn()

运行结果

"D:\Program Files\python33\python.exe" E:/Projects/interface_project_for_dev/teststudy.py

异常类型：

关联的值，或者需要raise的第二个参数： var is not an even number

异常发生点(根源)：

--------------------------

Traceback (most recent call last):

File "E:/Projects/interface_project_for_dev/teststudy.py", line 17, in testfn

AssertionError: var is not an even number

--------------------------

[('E:/Projects/interface_project_for_dev/teststudy.py', 44, '', 'testfn()'), ('E:/Projects/interface_project_for_dev/teststudy.py', 39, 'testfn', 'raw_traceback = traceback.extract_stack()')]

Process finished with exit code 0