In site.py, line 477, I find this code:

        # Reading the initialization (config) file may not be enough to set a
        # completion key, so we set one first and then read the file
        if 'libedit' in getattr(readline, '__doc__', ''):
            readline.parse_and_bind('bind ^I rl_complete')

I am using pyreadline on Windows, where readline.__doc__ is None.

So the above code crashes with this exception:

Python 3.4.0a1 (v3.4.0a1:46535f65e7f3, Aug  3 2013, 22:57:30) [MSC v.1600 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
Failed calling sys.__interactivehook__
Traceback (most recent call last):
  File "C:\Python34-64\lib\site.py", line 477, in register_readline
    if 'libedit' in getattr(readline, '__doc__', ''):
TypeError: argument of type 'NoneType' is not iterable