alt Hacker NewsPython has never followed the Zen. The irritating way the language lets you use non-booleans in a boolean context flies right in the face of "explicit is better than implicit".
Replies
loeg • yesterday at 8:38 PM
And typing wasn't explicit for a long time. Now it is kind of best practice, but you can still produce Python without typecheck metadata.
benji-york • today at 12:56 AM
Do you know why it is the way it is?
This will probably sound crazy to some of you, but I believe the introduction of the boolean type was a mistake.
Every primitive type has a null value, and the "if" statement tests for such a value. Whether a value is true or false is a property of the value. Notice that "true" and "false" are adjectives, not nouns.
That is a simple, internally consistent model with one concept of trueness.
The introduction of the boolean type made this a lot messier: it makes "if" look like type coercion, and introduces two different ways to think of boolean-ness (as an adjective or as a noun) which you must hold in your head at the same time. For example, it became possible to compare things as equal to True or False, doubling the number of ways to express a condition: "if x" and "if x == True" are now very similar, but subtly different, ways to express the same thing. The fact that we have to talk about things as "truthy" or "falsy" as if these were different from "true" and "false" is a further illustration of the mess this has created.
If we had stuck with 0 and 1, we would have avoided all this confusion. It is imperfect but simple; what we ended up with is still imperfect and needlessly complicated.