python2, python3에서 tuple의 덧셈 차이

python3에서는 두 튜플중 하나가 비어있으면 그냥 있던 튜플을 반환한다. 

Python 2.7.16 (default, Jun  5 2020, 22:59:21)
[GCC 4.2.1 Compatible Apple LLVM 11.0.3 (clang-1103.0.29.20) (-macos10.15-objc- on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> a = (1,2)
>>> b = ()
>>> c = a + b
>>> id(a)
4486121160
>>> id(c)
4486121016
>>>
[2]  + 21679 suspended  python2


 ✘ ⚙ jiwonwee@jiwon  ~  python3
Python 3.8.1 (v3.8.1:1b293b6006, Dec 18 2019, 14:08:53)
[Clang 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> a = (1,2)
>>> b = ()
>>> c = a+b
>>> id(a)
140267085238016
>>> id(c)
140267085238016