On Thu, Dec 31, 2009 at 11:13, davidj411 <davidj...@gmail.com> wrote:
> I am not sure why this behavior is this way.
> at beginning of script, i want to create a bunch of empty lists and
> use each one for its own purpose.
> however, updating one list seems to update the others.
>
>>>> a = b = c = []
>>>> a.append('1')
>>>> a.append('1')
>>>> a.append('1')
>>>> c
> ['1', '1', '1']
>>>> a
> ['1', '1', '1']
>>>> b
> ['1', '1', '1']That's because you're saying c is an empty list object, b is a pointer to the same list object and a is a pointer to the same list object. It looks better if you look at it like this: a \ b ------ [] c / You just created one actual object and created three pointers to it. Though I wondered something similar the other day... obviously this won't work: a,b,c = [] but does this do it properly: a,b,c = [],[],[] For now, in my newbieness, I've been just creating each one separately: a=[] b=[] c=[] Cheers, Jeff -- Jonathan Swift - "May you live every day of your life." - http://www.brainyquote.com/quotes/authors/j/jonathan_swift.html -- http://mail.python.org/mailman/listinfo/python-list
