In [105]: T1 = (1)  
In [106]: T2 = (2,3)  
In [107]: T1 + T2  
---------------------------------------------------------------------------  
TypeError                                 Traceback (most recent call last)  
<ipython-input-107-b105c7b32d90> in <module>()  
----> 1 T1 + T2;  
  
TypeError: unsupported operand type(s) for +: 'int' and 'tuple'  

In [108]: type(T1)  
Out[108]: int  
  
In [109]: T1 = (1,)  
In [110]: T2 = (2,3)  
In [111]: T1 + T2  
Out[111]: (1, 2, 3)