如何强制我的Python单元测试在错误日志之后打印回溯？

Question

我试图对一些复杂的网络内容进行单元测试，并且每次出现错误时，我的网络库都会输出数百行日志消息。 我唯一感兴趣的是错误的实际回溯，但是我必须向上滚动所有这些日志消息才能看到回溯。

有什么方法可以强制Python的unittest模块在日志后输出回溯，而不是其他方式？

例如，我目前看到以下内容：

======================================================================
ERROR: my_test (tests.MyTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "my_code_file.py", line 39, in my_function
    my_module.my_function()
  File "my_code_file.py", line 78, in my_function
    raise Exception("My exception here")
Exception: My exception here
-------------------- >> begin captured logging << --------------------
<<< hundreds of lines of logs from networking libraries/wiretraces/etc>>>
<<< hundreds of lines of logs from networking libraries/wiretraces/etc>>>
<<< hundreds of lines of logs from networking libraries/wiretraces/etc>>>
<<< hundreds of lines of logs from networking libraries/wiretraces/etc>>>
<<< hundreds of lines of logs from networking libraries/wiretraces/etc>>>
-------------------- >> end captured logging << --------------------

我希望看到这样的内容，以便在运行测试后可以快速看到错误：

======================================================================
-------------------- >> begin captured logging << --------------------
<<< hundreds of lines of logs from networking libraries/wiretraces/etc>>>
<<< hundreds of lines of logs from networking libraries/wiretraces/etc>>>
<<< hundreds of lines of logs from networking libraries/wiretraces/etc>>>
<<< hundreds of lines of logs from networking libraries/wiretraces/etc>>>
<<< hundreds of lines of logs from networking libraries/wiretraces/etc>>>
-------------------- >> end captured logging << --------------------
ERROR: my_test (tests.MyTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "my_code_file.py", line 39, in my_function
    my_module.my_function()
  File "my_code_file.py", line 78, in my_function
    raise Exception("My exception here")
Exception: My exception here

Answer 1

如何使用logging模块？

老实说，我不确定您将使用哪种功能以获得最佳效果。

但是，有logging.exception

EX：

import logging

try:
    print blah

except Exception, e:
    logging.exception("\n\n !!!!!! \n\n  {} \n\n !!!!!! \n\n".format(e))

可以看到该异常的输出：

ERROR:root:

 !!!!!! 

  name 'blah' is not defined 

 !!!!!! 

Traceback (most recent call last):
  File "<ipython-input-39-99d79696f33a>", line 2, in <module>
    print blah
NameError: name 'blah' is not defined