Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.python > #75868

Re: AttributeError: 'module' object has no attribute 'fork'

Show all headers | View raw

On Friday, August 8, 2014 11:18:17 AM UTC+5:30, Steven D'Aprano wrote:
> Rustom Mody wrote:

> > On Thursday, August 7, 2014 10:26:56 PM UTC+5:30, Steven D'Aprano wrote:
> >> Roy Smith wrote:
> >> >  Peter Otten  wrote:
> >> >> os.fork()
> >> >> Fork a child process.
> >> >> ...
> >> >> Availability: Unix.
> >> >> """
> >> >> You are using the wrong operating system ;)
> >> > To be honest, this could be considered a buglet in the os module.  It
> >> > really should raise:
> >> > NotImplementedError("fork() is only available on unix")
> >> > or perhaps even, as Peter suggests:
> >> > NotImplementedError("You are using the wrong operating system")
> >> > either of those would be better than AttributeError.
> >> I disagree. How would you tell if fork is implemented? With the current
> >> behaviour, telling whether fork is implemented or not is simple:
> >> is_implemented = hasattr(os, "fork")
> [...]
> > Surely I am missing something but why not check os.fork before
> > checking os.fork() ?

> Yes, you're missing something. That's what hasattr does.

> But with Roy's suggestion, testing for the existence of os.fork is not
> sufficient, because it will exist even on platforms where fork doesn't
> exist. So testing that os.fork exists is not sufficient to tell whether or
> not you can actually fork.

Windows:

Python 2.7.1 (r271:86832, Nov 27 2010, 18:30:46) [MSC v.1500 32 bit (Intel)] on win32
Type "copyright", "credits" or "license()" for more information.
>>> import os
>>> os.fork

Traceback (most recent call last):
  File "<pyshell#1>", line 1, in <module>
    os.fork
AttributeError: 'module' object has no attribute 'fork'


Linux:

$ python
Python 2.7.8 (default, Jul  4 2014, 13:08:34) 
[GCC 4.9.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> os.fork
<built-in function fork>
>>> 


So yes, I continue to miss something...

Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

AttributeError: 'module' object has no attribute 'fork' Satish ML <satishmlwizpro@gmail.com> - 2014-08-06 23:44 -0700
  Re: AttributeError: 'module' object has no attribute 'fork' Peter Otten <__peter__@web.de> - 2014-08-07 09:00 +0200
    Re: AttributeError: 'module' object has no attribute 'fork' Roy Smith <roy@panix.com> - 2014-08-07 07:49 -0400
      Re: AttributeError: 'module' object has no attribute 'fork' Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-08-08 02:56 +1000
        Re: AttributeError: 'module' object has no attribute 'fork' Rustom Mody <rustompmody@gmail.com> - 2014-08-07 22:19 -0700
          Re: AttributeError: 'module' object has no attribute 'fork' Rustom Mody <rustompmody@gmail.com> - 2014-08-07 22:35 -0700
          Re: AttributeError: 'module' object has no attribute 'fork' Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-08-08 15:48 +1000
            Re: AttributeError: 'module' object has no attribute 'fork' Rustom Mody <rustompmody@gmail.com> - 2014-08-08 00:17 -0700
              Re: AttributeError: 'module' object has no attribute 'fork' Chris Angelico <rosuav@gmail.com> - 2014-08-08 17:32 +1000

csiph-web