为什么这是这个 python 程序的输出？

Question

Someone from #python suggested that it's searching for module "herpaderp" and finding all the ones listed as its searching. If this is the case, why doesn't it list every module on my system before raising ImportError? Can someone shed some light on what's happening here?

import sys

class TempLoader(object):     
    def __init__(self, path_entry):
        if path_entry == 'test': return
        raise ImportError

    def find_module(self, fullname, path=None):
        print fullname, path
        return None

sys.path.insert(0, 'test')
sys.path_hooks.append(TempLoader)
import herpaderp

Answer 1

Looks like this is what's happening:

http://rhodesmill.org/brandon/2010/ubuntu-exception-190-modules/

Basically, the apport module (not part of the standard lib) gets tied in at a really low level to exceptions, like, before the exception is written to the stdout. So when the program fails to find "herpaderp", it throws an exception and triggers the import of apport and all the modules it contains and displays them in the output before the exception.

The solution? I have removed the “python-apport” package, along with the “ubuntuone-client” suite that depends on it. After the uninstall, exceptions are — wonderfully enough — not causing a single import of a new module! Now, finally, I can continue writing my import hook in peace.

Answer 2

Don't have a good answer as to why this is happening, but it differs between the two OSs I tested it on.

2.5.1 & 2.6.4 on Windows:

E:\work\python>python wtf.py
herpaderp None
Traceback (most recent call last):
  File "wtf.py", line 14, in <module>
    import herpaderp
ImportError: No module named herpaderp

E:\work\python>python --version
Python 2.5.1

2.5.2 on Linux:

$ python wtf.py
herpaderp None
apport None
subprocess None
... etc etc
_locale None
operator None
shutil None
Traceback (most recent call last):
  File "wtf.py", line 14, in <module>
    import herpaderp
ImportError: No module named herpaderp
$ python --version
Python 2.5.2

Sorry, that's not really an answer, but a bit too long to go in a comment!

Answer 3

😏 that's part of a pupy python module imho, it's for process injection. It won't work without a proper rpyc session which can supply the necessary modules as packaged messages which it unpacks and loads dynamically.

"