Coolest Python recipe of all time

[Ian Kelly]

On Tue, May 3, 2011 at 3:54 PM, Chris Angelico <rosuav at gmail.com> wrote:
> On Wed, May 4, 2011 at 2:43 AM, Raymond Hettinger <python at rcn.com> wrote:
>> We should have a separate thread for the most practical, best
>> documented, least surprising, and most boring recipe ;-)
>
> a += b   # Adds b to a in-place. Polymorphic - works on a wide variety of types.

Too surprising to qualify.  For some types it modifies a, while for
others it replaces a.