They are constants, like None, which has always been around.

True is False gives false in Python 2.7.18 as well as 3.x. But, in 2.x, they aren’t keywords, so you can say True=False=5 and then they are both the same object.

I just checked and they aren’t.

The builtin names are True and False and they became keywords a while back. true and false are just ordinary variables that you can set to whatever you want.

Meanwhile, in Forth:

: 2 3 ; \ define 2 as 3
2 2 + .  6 ok   \ shows that 2+2 is now 6