扭曲,延迟完全追溯

Question

我只是学习在Twisted上编写应用程序,所以犯了很多错误.

假设有一个代码:

d = defer.Deferred()
d.addCallback(self.start_app)
#d.addErrback(self.command_die)
d.callback(0)

def start_app(self, d):
    #import os
    return os.startfile(self.path)

def command_die(self, d):
    print ('com_die', d)

我们在os.startfile(self.path)和Big Traceback中有错误:

Unhandled error in Deferred:
Unhandled Error
Traceback (most recent call last):
  File "C:\Python27\lib\site-packages\twisted\internet\defer.py", line 542, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
  File "C:/Dropbox/my_py/client3.py", line 100, in command_analiz
    d.callback(i)
  File "C:\Python27\lib\site-packages\twisted\internet\defer.py", line 361, in callback
    self._startRunCallbacks(result)
  File "C:\Python27\lib\site-packages\twisted\internet\defer.py", line 455, in _startRunCallbacks
    self._runCallbacks()
--- <exception caught here> ---
  File "C:\Python27\lib\site-packages\twisted\internet\defer.py", line 542, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
  File "C:/Dropbox/my_py/client3.py", line 353, in start_eve_d
    return os.startfile(self.path)
exceptions.NameError: global name 'os' is not defined

如果我取消注释#d.addErrback(self.command_die)

我们通过print('com_die',d)创建了很少的"log":

('com_die', <twisted.python.failure.Failure <type 'exceptions.NameError'>>)

有没有办法在设计时获得完整的Log\TraceBack？

目前我要了解哪里出现了新的错误,有必要对addErrorback进行评论

Answer 1

Twisted Failure对象具有您需要的一切.为了获得良好的回溯尝试使用printTraceback()方法:

>>> from twisted.internet.defer import Deferred as D
>>> def start_app(_):
...     #import os
...     return os.startfile('sasa')
... 
... def command_die(err):
...     err.printTraceback()
... 
...     
... d = D()
... d.addCallback(start_app)
... d.addErrback(command_die)
... d.callback(0)
Traceback (most recent call last):
  File "C:\Users\Pilyavskiy\AppData\Local\DreamPie\share\dreampie\subp-py2\dreampielib\subprocess\__init__.py", line 324, in execute
    exec codeob in self.locs
  File "<pyshell#3>", line 12, in <module>
    d.callback(0)
  File "C:\pill\Python27\lib\site-packages\twisted\internet\defer.py", line 361, in callback
    self._startRunCallbacks(result)
  File "C:\pill\Python27\lib\site-packages\twisted\internet\defer.py", line 455, in _startRunCallbacks
    self._runCallbacks()
--- <exception caught here> ---
  File "C:\pill\Python27\lib\site-packages\twisted\internet\defer.py", line 542, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
  File "<pyshell#3>", line 3, in start_app
    return os.startfile('sasa')
exceptions.NameError: global name 'os' is not defined

在源代码http://twistedmatrix.com/trac/browser/tags/releases/twisted-8.2.0/twisted/python/failure.py#L121中查找其他选项,评论相当不错.

PS:名称d主要用于延迟本身,对于结果/错误,最好使用res/err等