子進程子追蹤

Question

我想訪問在子進程中運行的python程序的回溯。

The documentation說：的my_sub_program.py

Exceptions raised in the child process, before the new program has started to execute, will be re-raised in the parent. Additionally, the exception object will have one extra attribute called child_traceback, which is a string containing traceback information from the child’s point of view.

內容：的my_main_program.py

raise Exception("I am raised!") 

內容：

import sys 
import subprocess 
try: 
    subprocess.check_output([sys.executable, "my_sub_program.py"]) 
except Exception as e: 
    print e.child_traceback 

如果我跑my_main_program.py，我得到以下錯誤：

Traceback (most recent call last): 
    File "my_main_program.py", line 6, in <module> 
    print e.child_traceback 
AttributeError: 'CalledProcessError' object has no attribute 'child_traceback' 

如何在不修改子進程程序代碼的情況下訪問子進程的回溯？這意味着，我想避免在我的整個子程序代碼中添加一個大的try/except子句，而是處理來自主程序的錯誤日誌記錄。

編輯：sys.executable應該可以用與運行主程序的解釋器不同的解釋器替換。

Answer 1

當您啓動另一個Python進程時，您還可以嘗試使用Python模塊multiprocessing;由子類的Process類是很容易得到目標函數的異常：

from multiprocessing import Process, Pipe 
import traceback 
import functools 

class MyProcess(Process): 
    def __init__(self, *args, **kwargs): 
     Process.__init__(self, *args, **kwargs) 
     self._pconn, self._cconn = Pipe() 
     self._exception = None 

    def run(self): 
     try: 
      Process.run(self) 
      self._cconn.send(None) 
     except Exception as e: 
      tb = traceback.format_exc() 
      self._cconn.send((e, tb)) 
      # raise e # You can still rise this exception if you need to 

    @property 
    def exception(self): 
     if self._pconn.poll(): 
      self._exception = self._pconn.recv() 
     return self._exception 


p = MyProcess(target=functools.partial(execfile, "my_sub_program.py")) 
p.start() 
p.join() #wait for sub-process to end 

if p.exception: 
    error, traceback = p.exception 
    print 'you got', traceback 

關鍵是要有執行Python的子計劃的目標函數，這是通過使用functools.partial完成。