List append vs add

Thomas Wouters thomas at
Fri May 25 05:58:18 EDT 2001

On Fri, May 25, 2001 at 08:45:47AM +0100, Michael Hudson wrote:
> Tim Howarth <tim at> writes:

> > Is there any difference in result, performance or stylistic approval
> > ('niceness') of;
> > 
> > list.append('fred')
> > 
> > compared with,
> > 
> > list+=['fred']

> There is no difference in result.  The former strikes me as clearer,
> and might well be quicker.

It is quicker, but not by much. The += version skips the method lookup,
method call, and argument parsing that the .append version has to go
through, at the cost of a function-lookup in the type slot. The real work is
done in the same function in both cases, though, so you won't really notice
the difference.

Thomas Wouters <thomas at>

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