'11' + '1' is '111'?

[Benjamin Peterson]

metal <metal29a <at> gmail.com> writes:

> 
> '11' + '1' == '111' is well known.
> 
> but it suprises me '11'+'1' IS '111'.
> 
> Why? Obviously they are two differnt object.
> 
> Is this special feature of imutable object?

As other posters have pointed out, CPython does cache some small strings. In
this case, however, it's because '1' + '11' is constant folded.