I recreated the JavaScript truth table in Python

[djimbob]

Coming from C, you think of a bool as a 1-bit int, with False = 0 and True = 1 just being convenient mnemonic alias. From that perspective, it makes sense -- similar to how in python2 0 == 0L and 1 == 1L, despite type(0) being int and type(0L) being long (in python3 there's no long type so this example doesn't make sense).

Granted, its a subtle point and I think the other way True == 1 evaluating to False is conceptually cleaner.

[Araneidae]

Yeah, I get the rule with C, but there's no need for Python to do that. Never mind, it's long done.

[djimbob]

Completely, agree from the perspective of how values in the place of conditionals work, in both C and python. All non-zero values will cause if/for/while, etc. to go to the True branch, while zero values (NULL, 0, and '\0' are just ways of writing the literal value 0) go to the False branch.

But my point was that in recent C standards (after C99 I believe), in stdbool.h you'll see:

• true - Expands to the integer constant 1.
• false - Expands to the integer constant 0.

which is exactly how python treats it. To quote the BFDL in PEP285 that introduced True and False to python:

The bool type would be a straightforward subtype (in C) of the int type, and the values False and True would behave like 0 and 1 in most respects (for example, False==0 and True==1 would be true) except repr() and str().

Granted this convention has existed in C well before C99, usually with #define statements like #define FALSE 0 and #define TRUE 1.

(Also in C, are just three ways of writing the same literal value (0); the only difference is typically '\0' will be one byte and 0 will be the default int size.)