[Python-Dev] Re: C's for statement

Thomas Wouters thomas@xs4all.net
Tue, 30 Jan 2001 07:14:20 +0100

On Mon, Jan 29, 2001 at 09:34:01PM -0500, Eric S. Raymond wrote:

> I guess my archetype of the cute C for-loop is the idiom for 
> pointer-list traversal:

> 	struct foo {int data; struct foo *next;} *ptr, *head; 

> 	for (ptr = head; *ptr; ptr = ptr->next)
> 		do_something_with(ptr->data)

Note two things: in Python, you would use a list, so 'for x i list' does
exactly what you want here ;) And if you really need it, you could use
iterators for exactly this (once we have them, of course): you are inventing
a new storage type. Quite common in C, since the only one it has is useless
for anything other than strings<wink>, but not so common in Python.

> Not the highest on my list of wants -- I'd sooner have ?: back.  I submitted
> a patch for that once, and the discussion sort of died.  Were you dead
> det against it, or should I revive this proposal?

Triple blech. Guido will never go for it! (There, increased your chance of
getting it approved! :) Seriously though, I wouldn't like it much, it's too
cryptic a syntax. I notice I use it less and less in C, too.

Thomas Wouters <thomas@xs4all.net>

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