Why doesn't this work?

[Jeremy Jones]

* Courageous (jkraska at san.rr.com) wrote:
> 
> Python 2.2b2 (#26, Nov 16 2001, 11:44:11) [MSC 32 bit (Intel)] on
> win32
> Type "copyright", "credits" or "license" for more information.
> IDLE 0.8 -- press F1 for help
> >>> def f(): return [1,2,3]
> 
> >>> f()
> [1, 2, 3]
> >>> f().append(4)
> >>> l=f().append(4)
> >>> l
> >>> 

I'll let someone else address why this doesn't work.  I couldn't tell you.  Intuitively, it really looks like it should not work and that Python is behaving properly.  But if you do this:

>>> def f():
	return [1,2,3]

>>> f()
[1, 2, 3]
>>> l = f()
>>> l
[1, 2, 3]
>>> l.append(4)
>>> l
[1, 2, 3, 4]
>>> 

I think you get behavior closer to what you were looking for.  When you did:
> >>> f().append(4)
it doesn't seem like the [1, 2, 3] "IS" anywhere for you to append anything to it.  It seems like you should have to put it into something before you can do anything with it.


Jeremy Jones