a = 1000 b = 1000 a is b The output is false only if you use the REPL. Run a .py script writing the above code and it returns True. I read about it on SO but

a = 1000 b = 1000 a is b The output is false only if you use the REPL. Run a .py script writing the above code and it returns True. I read about it on SO but can't find the link to it!