How can I create a linked list in Python?
Thu Jan 18 00:11:09 CET 2007
"sturlamolden" <sturlamolden at yahoo.no> writes:
> Actually, nesting tuples or lists doesn't really duplicate Lisp cons,
> as one can only create a stack-like object with the nesting. Python
> really need a cons type like Lisp. I think it is time to write one, in
> a plain C extension.
But that's what Lisp does too. As the poet said:
One thing the average language lacks
Is programmed use of push-down stacks.
But LISP provides this feature free:
A stack - you guessed it - is a tree.
An empty stack is simply NIL.
In order, then, the stack to fill
A CONS will push things on the top;
To empty it, a CDR will
Behave exactly like a pop.
A simple CAR will get you back
The last thing you pushed on the stack;
An empty stack's detectable
By testing with the function NULL.
Thus even should a LISPer lose
With PROGs and GOs, RETURNs and DOs,
He need his mind not overtax
To implement recursive hacks:
He'll utilize this clever ruse
Of using trees as moby stacks.
All Python needs is a way of displaying the lists as (a b c) instead
of [a, [b, [c, None]]], and that can be done in pure Python.
More information about the Python-list