Error while concatenating str and int objects

consider a case through below code snippet

str_val = "Test_"
int_val = 1
print (str_val + int_val)

I have a static string and the int_val is coming from some loop. I need to concatenate them both and store it into some runtime variable.

But i am getting error as:

TypeError                                 Traceback (most recent call last)
~\AppData\Local\Temp/ipykernel_31208/ in <module>
      1 str_val = "Test_"
      2 int_val = 1
----> 3 print (str_val + int_val)

TypeError: can only concatenate str (not "int") to str

What to do ?