Python中的调试：显示最后N行执行的代码

我希望看到python解释器在发生此异常之前执行的最后10行：

test_has_perm_in_foobar.py F
Traceback (most recent call last):
  File "/.../test_has_perm_in_foobar.py", line 50, in test_has_perm
    self.assertFalse(check_perm(request, some_object))
  File "/usr/lib/python2.7/unittest/case.py", line 416, in assertFalse
    raise self.failureException(msg)
AssertionError: True is not false

我想看看哪里

check\u perm（）

返回了

True

我知道我可以使用交互式调试来查找匹配的行，但我很懒，希望找到一种更简单的方法来查找

check\u perm（）

返回返回值的行

我使用pyCharm，但基于文本的工具也能解决我的需要

顺便说一句：请不要告诉我如何使用带有单步跳过和单步进入的调试器。我知道这一点

下面是一些代码来说明它

def check_perm(request, some_object):
    if condition_1:
        return True
    if condition_2:
        return sub_check(some_object)
    if condition_3:
        return sub_check2(some_object)
    ...

有几种方法可以让

check\u perm（）

返回

True

。如果由于条件_1而返回了

True

，那么我希望看到类似的情况

+         if condition_1:
+            return True

我心目中的输出类似于shell上的

set-x

更新 cgib、pytest和其他工具可以显示断言失败的行之前的行。但是，它们只显示当前python文件的行。这个问题是关于在断言发生之前执行的行，但涵盖所有文件。在我的例子中，我想知道

check\u perm（）

的返回值是在哪里创建的。pytest、cgitb等工具。。。不要展示这个

我正在搜索的是shell上的

set-x

：

帮助设置

-x打印命令及其执行时的参数

---

那么cgitb如何？您只需要将此模块导入到代码中

import cgitb
cgitb.enable(format='text')

def f():
    a = 1
    b = 2
    c = 3
    x = 0
    d = a * b * c / x
    return d

if __name__ == "__main__":
    f()

给出：

ZeroDivisionError
Python 3.5.2: /usr/bin/python3
Mon Dec 19 17:42:34 2016

A problem occurred in a Python script.  Here is the sequence of
function calls leading up to the error, in the order they occurred.
 /home/user1/123.py in <module>()
   10     d = a * b * c / x
   11     return x
   12 
   13 if __name__ == "__main__":
   14     f()
f = <function f>
 /home/user1/123.py in f()
    8     c = 3
    9     x = 0
   10     d = a * b * c / x
   11     return x
   12 
d undefined
a = 1
b = 2
c = 3
x = 0
ZeroDivisionError: division by zero
...
The above is a description of an error in a Python program.  Here is
the original traceback:

Traceback (most recent call last):
  File "123.py", line 14, in <module>
    f()
  File "123.py", line 10, in f
    d = a * b * c / x
ZeroDivisionError: division by zero

zero错误
Python 3.5.2:/usr/bin/python3
2016年12月19日星期一17:42:34
Python脚本中出现问题。下面是一系列的步骤
导致错误的函数调用，按发生顺序排列。
/home/user1/123.py in（）
10 d=a*b*c/x
11返回x
12
13如果名称=“\uuuuu main\uuuuuuuu”：
14 f（）
f=
/f（）中的home/user1/123.py
8 c=3
9 x=0
10 d=a*b*c/x
11返回x
12
d未定义
a=1
b=2
c=3
x=0
ZeroDivision错误：被零除
...
上面是Python程序中错误的描述。这是
原始回溯：
回溯（最近一次呼叫最后一次）：
文件“123.py”，第14行，在
f（）
文件“123.py”，第10行，在f中
d=a*b*c/x
ZeroDivision错误：被零除

由于找不到解决方案，我自己写了以下内容：

with trace_function_calls():    
    self.assertFalse(check_perm(request, some_object))

跟踪函数调用（）的实现：

---

PS：这是开源软件。如果你想创建一个python包，那么就去做吧，告诉我，这会让我很高兴。

出于这个原因，我把测试切换到了

它可以显示局部变量，并以不同的去目标化水平进行回溯。完成调用的行标记为

例如，在我的django项目中：

$ py.test --showlocals --tb=long
=============================== test session starts ===============================
platform darwin -- Python 3.5.1, pytest-3.0.3, py-1.4.31, pluggy-0.4.0
Django settings: dj_tg_bot.settings (from ini file)
rootdir: /Users/el/Projects/dj-tg-alpha-bot, inifile: tox.ini
plugins: django-3.0.0, cov-2.4.0
collected 8 items

tests/test_commands.py ....F
tests/test_logger.py .
tests/test_simple.py ..

==================================== FAILURES =====================================
__________________________ TestSimpleCommands.test_start __________________________

self = <tests.test_commands.TestSimpleCommands testMethod=test_start>

    def test_start(self,):
        """
            Test bot accept normally command /start and replies as it should.
            """
>       self._test_message_ok(self.start)

self       = <tests.test_commands.TestSimpleCommands testMethod=test_start>

tests/test_commands.py:56:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <tests.test_commands.TestSimpleCommands testMethod=test_start>
action = {'in': ' /start', 'out': {'parse_mode': 'Markdown', 'reply_markup': '', 'text': 'Welcome'}}
update = <telegram.update.Update object at 0x113e16cf8>, number = 1

    def _test_message_ok(self, action, update=None, number=1):
        if not update:
            update = self.update
        with mock.patch("telegram.bot.Bot.sendMessage", callable=mock.MagicMock()) as mock_send:
            if 'in' in action:
                update.message.text = action['in']
            response = self.client.post(self.webhook_url, update.to_json(), **self.kwargs)
            #  Check response 200 OK
            self.assertEqual(response.status_code, status.HTTP_200_OK)
            #  Check
>           self.assertBotResponse(mock_send, action)

action     = {'in': ' /start', 'out': {'parse_mode': 'Markdown', 'reply_markup': '', 'text': 'Welcome'}}
mock_send  = <MagicMock name='sendMessage' id='4619939344'>
number     = 1
response   = <Response status_code=200, "application/json">
self       = <tests.test_commands.TestSimpleCommands testMethod=test_start>
update     = <telegram.update.Update object at 0x113e16cf8>

../../.pyenv/versions/3.5.1/lib/python3.5/site-packages/telegrambot/test/testcases.py:83:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <tests.test_commands.TestSimpleCommands testMethod=test_start>
mock_send = <MagicMock name='sendMessage' id='4619939344'>
command = {'in': ' /start', 'out': {'parse_mode': 'Markdown', 'reply_markup': '', 'text': 'Welcome'}}

    def assertBotResponse(self, mock_send, command):
>       args, kwargs = mock_send.call_args
E       TypeError: 'NoneType' object is not iterable

command    = {'in': ' /start', 'out': {'parse_mode': 'Markdown', 'reply_markup': '', 'text': 'Welcome'}}
mock_send  = <MagicMock name='sendMessage' id='4619939344'>
self       = <tests.test_commands.TestSimpleCommands testMethod=test_start>

../../.pyenv/versions/3.5.1/lib/python3.5/site-packages/telegrambot/test/testcases.py:61: TypeError
------------------------------ Captured stderr call -------------------------------
Handler not found for {'message': {'from': {'username': 'username_4', 'last_name': 'last_name_4', 'id': 5, 'first_name': 'first_name_4'}, 'chat': {'username': 'username_4', 'last_name': 'last_name_4', 'first_name': 'first_name_4', 'title': 'title_4', 'type': 'private', 'id': 5}, 'text': ' /start', 'message_id': 5, 'date': 1482500826}, 'update_id': 5}
======================= 1 failed, 7 passed in 2.29 seconds ========================
(.env) ✘-1 ~/Projects/dj-tg-alpha-bot [master|✚ 1…8⚑ 12]
16:47 $

$py.test--showlocals--tb=long
==============================================测试会话开始===============================
平台darwin——Python 3.5.1、pytest-3.0.3、py-1.4.31、Plugy-0.4.0
Django设置：dj_tg_bot.settings（来自ini文件）
rootdir:/Users/el/Projects/dj-tg-alpha-bot，ini文件：tox.ini
插件：django-3.0.0、cov-2.4.0
收集了8个项目
tests/test_commands.py…F
测试/test_logger.py。
测试/测试_simple.py。。
======================================================故障=====================================
__________________________TestSimpleCommand.test\u启动__________________________
自我=
def测试_启动（自）
"""
测试bot正常接受命令/启动，并按其应该的方式回复。
"""
>self.\u测试\u消息\u正常（self.start）
自我=
测试/测试_命令。py:56：
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
自我=
action={'in'：'/start'，'out'：{'parse_mode'：'Markdown'，'reply_markup'：''，'text'：'Welcome'}
更新=，编号=1
def _测试_消息_ok（自我、操作、更新=无，编号=1）：
如果没有更新：
update=self.update
使用mock.patch（“telegram.bot.bot.sendMessage”，callable=mock.MagicMock（））作为mock_发送：
如果“正在”运行：
update.message.text=操作['in']
response=self.client.post（self.webhook_url，update.to_json（），**self.kwargs）
#检查响应200 OK
self.assertEqual（response.status\u代码，status.HTTP\u 200\u OK）
#检查
>self.assertBotResponse（模拟发送，操作）
action={'in'：'/start'，'out'：{'parse_mode'：'Markdown'，'reply_markup'：''，'text'：'Welcome'}
模拟发送=
数字=1
答复=
自我=
更新=
../../.pyenv/versions/3.5.1/lib/python3.5/site packages/telegrambot/test/testcases.py:83：
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
自我=
模拟发送=
command={'in'：'/start'，'out'：{'parse_mode'：'Markdown'，'reply_markup'：''，'text'：'Welcome'}
def assertBotResponse（自我、模拟发送、命令）：
>args，kwargs=mock\u send.call\u args
E类型错误：“非类型”对象不可编辑
command={'in'：'/start'，'out'：{'parse_mode'：'Markdown'，'reply_markup'：''，'text'：'Welcome'}
模拟发送=
自我=
../...pyenv/versions/3.5.1/lib/python3.5/site packages/telegrambot/test/testcases.py:61:TypeError
------------------------------捕获的stderr调用-------------------------------
未找到{'message'：{'from'：{'username'：'username\u 4'，'last\u name'：'last\u name\u 4'，'id'：5'，'first\u name'：'first\u name\u 4'，chat'：{'username'：'username\u 4'，'first\u name'：'first\u name\u 4'，'title'：'title'：'title\u 4'，'type'：'private'，'id'：5}，'text'：'start'，'message id'：5'，date 2500826}，“更新id”：5}
==================================1失败，2.29秒内通过7次========================
（.env）✘-1~/Projects/dj tg阿尔法机器人[主|✚ 1…8⚑ 12]
16:47 $

模块具有与bourne兼容的外壳

set-x

类似的功能

$ py.test --showlocals --tb=long
=============================== test session starts ===============================
platform darwin -- Python 3.5.1, pytest-3.0.3, py-1.4.31, pluggy-0.4.0
Django settings: dj_tg_bot.settings (from ini file)
rootdir: /Users/el/Projects/dj-tg-alpha-bot, inifile: tox.ini
plugins: django-3.0.0, cov-2.4.0
collected 8 items

tests/test_commands.py ....F
tests/test_logger.py .
tests/test_simple.py ..

==================================== FAILURES =====================================
__________________________ TestSimpleCommands.test_start __________________________

self = <tests.test_commands.TestSimpleCommands testMethod=test_start>

    def test_start(self,):
        """
            Test bot accept normally command /start and replies as it should.
            """
>       self._test_message_ok(self.start)

self       = <tests.test_commands.TestSimpleCommands testMethod=test_start>

tests/test_commands.py:56:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <tests.test_commands.TestSimpleCommands testMethod=test_start>
action = {'in': ' /start', 'out': {'parse_mode': 'Markdown', 'reply_markup': '', 'text': 'Welcome'}}
update = <telegram.update.Update object at 0x113e16cf8>, number = 1

    def _test_message_ok(self, action, update=None, number=1):
        if not update:
            update = self.update
        with mock.patch("telegram.bot.Bot.sendMessage", callable=mock.MagicMock()) as mock_send:
            if 'in' in action:
                update.message.text = action['in']
            response = self.client.post(self.webhook_url, update.to_json(), **self.kwargs)
            #  Check response 200 OK
            self.assertEqual(response.status_code, status.HTTP_200_OK)
            #  Check
>           self.assertBotResponse(mock_send, action)

action     = {'in': ' /start', 'out': {'parse_mode': 'Markdown', 'reply_markup': '', 'text': 'Welcome'}}
mock_send  = <MagicMock name='sendMessage' id='4619939344'>
number     = 1
response   = <Response status_code=200, "application/json">
self       = <tests.test_commands.TestSimpleCommands testMethod=test_start>
update     = <telegram.update.Update object at 0x113e16cf8>

../../.pyenv/versions/3.5.1/lib/python3.5/site-packages/telegrambot/test/testcases.py:83:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <tests.test_commands.TestSimpleCommands testMethod=test_start>
mock_send = <MagicMock name='sendMessage' id='4619939344'>
command = {'in': ' /start', 'out': {'parse_mode': 'Markdown', 'reply_markup': '', 'text': 'Welcome'}}

    def assertBotResponse(self, mock_send, command):
>       args, kwargs = mock_send.call_args
E       TypeError: 'NoneType' object is not iterable

command    = {'in': ' /start', 'out': {'parse_mode': 'Markdown', 'reply_markup': '', 'text': 'Welcome'}}
mock_send  = <MagicMock name='sendMessage' id='4619939344'>
self       = <tests.test_commands.TestSimpleCommands testMethod=test_start>

../../.pyenv/versions/3.5.1/lib/python3.5/site-packages/telegrambot/test/testcases.py:61: TypeError
------------------------------ Captured stderr call -------------------------------
Handler not found for {'message': {'from': {'username': 'username_4', 'last_name': 'last_name_4', 'id': 5, 'first_name': 'first_name_4'}, 'chat': {'username': 'username_4', 'last_name': 'last_name_4', 'first_name': 'first_name_4', 'title': 'title_4', 'type': 'private', 'id': 5}, 'text': ' /start', 'message_id': 5, 'date': 1482500826}, 'update_id': 5}
======================= 1 failed, 7 passed in 2.29 seconds ========================
(.env) ✘-1 ~/Projects/dj-tg-alpha-bot [master|✚ 1…8⚑ 12]
16:47 $

import sys
import trace
import unittest

from app import check_perm

tracer = trace.Trace(trace=1, ignoredirs=(sys.prefix, sys.exec_prefix))

class Test(unittest.TestCase):
    def test_one(self):
        tracer.runctx('self.assertFalse(check_perm("dummy", 3))', globals(), locals())

if __name__ == '__main__':
    unittest.main()

def sub_check1(some_object):
    if some_object * 10 == 20:
        return True

def sub_check2(some_object):
    if some_object * 10 == 30:
        return True

def check_perm(request, some_object):
    if some_object == 1:
        return True
    if some_object == 2:
        return sub_check1(some_object)
    if some_object == 3:
        return sub_check2(some_object)

$ python test_has_perm_in_foobar.py 
 --- modulename: test_has_perm_in_foobar, funcname: <module>
<string>(1):   --- modulename: app, funcname: check_perm
app.py(10):     if some_object == 1:
app.py(12):     if some_object == 2:
app.py(14):     if some_object == 3:
app.py(15):         return sub_check2(some_object)
 --- modulename: app, funcname: sub_check2
app.py(6):     if some_object * 10 == 30:
app.py(7):         return True
F
======================================================================
FAIL: test_one (__main__.Test)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test_has_perm_in_foobar.py", line 23, in test_one
    tracer.runctx('self.assertFalse(check_perm("dummy", 3))', globals(), locals())
  File "/usr/lib/python2.7/trace.py", line 513, in runctx
    exec cmd in globals, locals
  File "<string>", line 1, in <module>
AssertionError: True is not false

----------------------------------------------------------------------
Ran 1 test in 0.006s

FAILED (failures=1)

import trace
import unittest

from app import check_perm

tracer = trace.Trace(trace=1)

class Test(unittest.TestCase):
    def test_one(self):
        self.assertFalse(tracer.runfunc(check_perm, 'dummy', 3))

if __name__ == '__main__':
    unittest.main()

$ python test_has_perm_in_foobar.py
 --- modulename: app, funcname: check_perm
app.py(10):     if some_object == 1:
app.py(12):     if some_object == 2:
app.py(14):     if some_object == 3:
app.py(15):         return sub_check2(some_object)
 --- modulename: app, funcname: sub_check2
app.py(6):     if some_object * 10 == 30:
app.py(7):         return True
F
======================================================================
FAIL: test_one (__main__.Test)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test_has_perm_in_foobar.py", line 19, in test_one
    self.assertFalse(tracer.runfunc(check_perm, 'dummy', 3))
AssertionError: True is not false

----------------------------------------------------------------------
Ran 1 test in 0.005s

FAILED (failures=1)

import pytest

@pytest.mark.A
def test_add():

  a = 1
  b = 2

  add(a,b)

def add(a, b):
  assert a>b

  return a+b

def main():
  add(1,2)
  add(2,1)

if __name__ == "__main__":
  # execute only if run as a script
  main()

art@macky ~/src/python/so-answer-stacktrace: py.test -v --tb=short -m A code.py
============================= test session starts ==============================
platform darwin -- Python 2.7.5 -- pytest-2.5.0 -- /Users/art/.pyenv/versions/2.7.5/bin/python
collected 1 items

code.py:3: test_add FAILED

=================================== FAILURES ===================================
___________________________________ test_add ___________________________________
code.py:9: in test_add
>     add(a,b)
code.py:12: in add
>     assert a>b
E     assert 1 > 2
=========================== 1 failed in 0.01 seconds ===========================

def add(a, b):
  from pdb import set_trace;set_trace()
  assert a>b

  return a+b

art@macky ~/src/python/so-answer-stacktrace: py.test -v --tb=short -m A code.py
=========================================================================================== test session starts ============================================================================================
platform darwin -- Python 2.7.5 -- pytest-2.5.0 -- /Users/art/.pyenv/versions/2.7.5/bin/python
collected 1 items

code.py:3: test_add
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> PDB set_trace (IO-capturing turned off) >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
> /Users/art/src/python/so-answer-stacktrace/code.py(13)add()
-> assert a>b
(Pdb)

(Pdb) w
  /Users/art/.pyenv/versions/2.7.5/bin/py.test(9)<module>()
-> load_entry_point('pytest==2.5.0', 'console_scripts', 'py.test')()
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/config.py(19)main()
-> return config.hook.pytest_cmdline_main(config=config)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/core.py(376)__call__()
-> return self._docall(methods, kwargs)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/core.py(387)_docall()
-> res = mc.execute()
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/core.py(288)execute()
-> res = method(**kwargs)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/main.py(111)pytest_cmdline_main()
-> return wrap_session(config, _main)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/main.py(81)wrap_session()
-> doit(config, session)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/main.py(117)_main()
-> config.hook.pytest_runtestloop(session=session)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/core.py(376)__call__()
-> return self._docall(methods, kwargs)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/core.py(387)_docall()
-> res = mc.execute()
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/core.py(288)execute()
-> res = method(**kwargs)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/main.py(137)pytest_runtestloop()
-> item.config.hook.pytest_runtest_protocol(item=item, nextitem=nextitem)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/core.py(376)__call__()
-> return self._docall(methods, kwargs)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/core.py(387)_docall()
-> res = mc.execute()
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/core.py(288)execute()
-> res = method(**kwargs)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/runner.py(62)pytest_runtest_protocol()
-> runtestprotocol(item, nextitem=nextitem)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/runner.py(72)runtestprotocol()
-> reports.append(call_and_report(item, "call", log))
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/runner.py(106)call_and_report()
-> call = call_runtest_hook(item, when, **kwds)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/runner.py(124)call_runtest_hook()
-> return CallInfo(lambda: ihook(item=item, **kwds), when=when)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/runner.py(137)__init__()
-> self.result = func()
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/runner.py(124)<lambda>()
-> return CallInfo(lambda: ihook(item=item, **kwds), when=when)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/main.py(161)call_matching_hooks()
-> return hookmethod.pcall(plugins, **kwargs)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/core.py(380)pcall()
-> return self._docall(methods, kwargs)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/core.py(387)_docall()
-> res = mc.execute()
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/core.py(288)execute()
-> res = method(**kwargs)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/runner.py(86)pytest_runtest_call()
-> item.runtest()
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/python.py(1076)runtest()
-> self.ihook.pytest_pyfunc_call(pyfuncitem=self)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/main.py(161)call_matching_hooks()
-> return hookmethod.pcall(plugins, **kwargs)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/core.py(380)pcall()
-> return self._docall(methods, kwargs)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/core.py(387)_docall()
-> res = mc.execute()
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/core.py(288)execute()
-> res = method(**kwargs)
  /Users/art/.pyenv/versions/2.7.5/lib/python2.7/site-packages/pytest-2.5.0-py2.7.egg/_pytest/python.py(188)pytest_pyfunc_call()
-> testfunction(**testargs)
  /Users/art/src/python/so-answer-stacktrace/code.py(9)test_add()
-> add(a,b)
> /Users/art/src/python/so-answer-stacktrace/code.py(13)add()
-> assert a>b
(Pdb)