The "ter" comes from Latin, where "ter" means "three times" and "tres" just means "three", "ternus" is treefold and so on. So ternary ("ternarius") is three-ish, having the quality of three, being composed of partes tres (three parts). The root of "tri" lies in ancient Greek. So it's just a matter of which fancy dead language you find cooler to flex your smarts, when naming things.

It's worth noting that there is merit to calling ?: in any form a "conditional expression." 'Ternary operators' are operators which accept 3 arguments, no matter what they do. For example, I could define a mathematical ternary operator [a $ b $ c ↦a * c - b]. The only reason programmers know what "the" ternary operator does is because afaik there is only one such operator (up to operator symbol and argument order) that is ever defined in any practical language, that being [a ? b : c].

What's funny is that the python community held a vote for the ternary operator syntax. They came to a consensus on what syntax to use, then Guido came in and used his own.

It didn't take me too long to learn to check date stamps on stack overflow for this very reason.

I literally had the same idea of flagging SO posts as outdated sometime ago, it would solve so many issues with outdated answers!

"Ternary (from Latin ternarius) or trinary is an adjective meaning 'composed of three items'." From Wikipedia

How to learn Python? Many tutorials I don`t know where to get started

Stale info is turning into a huge annoyance on the internet. Now when searching stack overflow you often times have to pay attention to the dates just to make sure the answers aren't over a decade old! Sometimes that's fine, with python that's usually a huge problem.

It's called ternary because it comes from Latin. "bīnus" is twofold, "ternus" is threefold, "quaternārius" is fourfold and so on

2:35 The one good place for these is golf code, where ``[a,b][cond]`` is the shortest way to evaluate conditionals in python. If you don't want b to be evaluated when not returned (maybe for recursion), you can use ``a * cond or b``. If a also can't be evaluated, you use ``cond and a or b``, which still saves 2 characters over the if-else syntax. That said, golf code != good code, don't put this in your projects!

Lol sometimes the appropriate edit for a very old SO post.. is to delete it. I don't think people have the heart for that

Great video! An important discussion is when to use conditional expressions (ternary operators) in Python? There is a tradeoff between efficiency vs. readability. For short expressions, the conditional expression is certainly a great tool. But if the expressions are long, I prefer to write out the if-else on separate lines as this improves the readability. I also never use the conditional expressions in my own videos as not everyone is aware of them, to avoid alianating people.

Valid criticism of stackoverflow at the end. I wish you'd explained exactly why those answers are wrong.

Thank you for another great video! And please tune up your volume a bit, you sound way quieter than most youtubers.

Seeing your facial expressions while discussing the oddities of Python is very satisfying hehe

“Ter” is the prefix used in *ordinal* numbers. Same as we say _third,_ not _threed._ So… one, two, three vs. primary, secondary, tertiary. Somebody must have conceptualized the operation as ordinal (e.g., taking a third value) rather than cardinal (e.g., taking 3 values).

I really don't like Python's ternary. For anything non-trivial, the flipped order makes it confusing to read. I mostly use it only on list comprehensions or when the condition or expressions are trivial; otherwise, I prefer an if/else block.

Great examples of use cases where conditional expressions can be used. E.g. for setting a default immutable value.

short simple and concise. Loved it!

The third answer on StackOverflow mentiones that the answer is for Python versions before 2.5 so it's ok

Oh, I'd been using the wrong ones for a while now. Didn't know there was an official version now! 😅

"Deprecated" might do the job of "Severely Out Of Date" without negative impact on reputation.

Good advice for stack of. 👍👍

The problem with c and x or y is that when x evaluates falsey it still results in y even though that's incorrect behavior compared to x if c else y

Re Stack Overflow: Fix your sort. It's set to "Highest Score" instead of "Trending". This should generally be good enough.

Me and My homie : "Stuff the codes into 1 line and sent it to the teacher."

i gotta try that last one

That's just one of the ternary operators. A[b:c] is another. The adjective 'ternary' was borrowed from mathematics. 'Trinary' seems to be used only by astronomers.

Standard stackoverflow. Systemic problem with no solution that is at least partially caused by overeager mods.

I would have preferred the C-style syntax of: x = if ( cond ) a else b; # as in making it ternary by explicitly using parens, but that's probably just me. Of course, I still haven't settled on a clean syntax in that regard for my own language. Far too many years have passed for me to be undecided.

Conditional operator is different from ternary, because you can't use it as a reference. (my_score if winner == "me" else opponent_score) += 1 won't work in python. (winner == "me" ? my_score : opponent_score)++ Works in C++.

The walrus operator is next I guess.

Can't argue with option Q.

0:15 Python is too cool for using question mark in its ternary operator because its aim is to create code that reads like english, not some symbol soup like Perl.

Middle English, from Latin ternarius, from terni three each; akin to Latin tres three

ternary from tertiary (primary, secondary, tertiary)

using a tuple method still useful in code golf :)

the one-liner

Why "bonkers"? This was probably borrowed from Lua and it actually works in Python. Not to say, that it's more elegant :)

I always wondered why bools are also integers. (False+3)*(4-True) returns 9 And isinstance(True, int) returns True

Ahhh this was a short

1:04 Lol, imagine if they chose N instead.

Python ternary can be more complex, such as : z = 'positive' if x > 0 else 'negative' if x < 0 else 'zero'

Unlike c++ you can't "assign" ternary expression to something while you can "assign" something to it In other words you can't do this x=y=0 (x if True else y) = 1

So, multiple if statements at the same time?

I have zero problem with the wordiness of "if else" instead of "? :", but the order would throw me. It looks almost as bad as an "unless" statement in Perl. Which is so bad a construct that Mark Rendle featured it as the only means of conditional testing in his hypothetical "The Worst Programming Language Ever" stump speech. It wouldn't be so clumsy if it followed the same order as if...else statements, but alas, it doesn't even do that. On the plus side, anything that allows an expression instead of a statement is progress.

cool

the other answers are useful when golfing

It might be unusal style but what is wrong with (FalseStatement, TrueStatement)[test]? Granded it will excute both statements so be aware of that, otherwise it is fine. Also which purpose did they serve back then, that they don't do now? Just tested, the trick still works with Python 3.11.

My fave is: a = None b = 2 var = a or 2

I’m not a fan of this shortcut, my brain likes to see the extra 3 lines 😅

Surely it should be called a binary operator? It returns (and only returns) one of two possible options.

Thats not a ternary operator. I can say that not as a programmer but as a mathematician. For one thing its not ternary, and for a second thing is not an operator. Its unary. There is a single input argument: the condition. Based on that argument (True or False) you get the output of the operator. A single input with two possible values get mapped in a one-to-one correspondence to one output with two different possible values. Contrast the number of inputs with that of a binary operator, say, an addition operation, which clearly requires two inputs. The function youre talking about does not have three inputs. It doesnt even have two. It (the IF function) gives one output for its one input (a boolean), and you assign the possible outputs to it, as you would with any function, binary, unary, or otherwise. A ternary function would take three arguments as input and provide you with a fourth value, an output Its not even an operator. Its a function. An operator gives as output an entity (or class, if you will) of like-type as each of its argument inputs, all of which are also of like-type. Such as the addition of integers, for example. The IF statement takes a boolean as an input argument and returns any class of statement you want it to. As an amateur philologist and etymologist I can comment on the prefix as well. It does also tie into my mathematics expertise, too. The difference between ter and tri is the difference between Latin origins and Greek origins. Generally the grammatical rule is to use the same language for prefixes and for suffixes as you used for the root word. Thats why we can say either quadrilateral (more common) or tetragon for a four-sided shape. One would not say tetralateral or quadrigon. One takes the Greek root and the other the Latin root. Technically one counts the number of sides and the other counts the number of angles. Indeed, the proper pluralization of octopus is octopodes, not octopi. Octopus is a Greek word and pseudointellectuals in English used the Latin pluralization to come up with octopi.

Isn’t it “tertiary”?

I personally find the Python construct to be a complete abortion. Here is what I prefer to use: («if-false-val», «if-true-val»)[«bool-val»] or if you want lazy evaluation: (lambda : «if-false-val», lambda : «if-true-val»)[«bool-val»]() The nice thing is, this generalizes nicely to a multiway switch-expression, which C and its derivatives don’t have.

1:17 Yet another reason why it’s a stupid design.