The BIGGEST Misconception About Type Hints In Python Explained 

Oh, that's actually another common misconception with terminology. Python IS a strongly typed language. People tend to mix two separate ways of classification, which are Strong/weak vs static dynamic. Python has a strong dynamic typing.

@@evlezzz Oh interesting. So what the commenter ment is more the Static Typing part?

I mostly care about intellisense. Sometimes I even create “dummy” modules to import just with type information to allow intellisense to work.

@@mattizzle81 a great way to import "dummy" modules just for type hinting is to do the following: from typing import TYPE_CHECKING if TYPE_CHECKING: from dummy.module import DummyType now it will only import "DummyType" when intellisense is type checking.

this can also help prevent import cycle errors

Most of the times good IDEs can infer what a variable is supposed to contain. So I agree But some hairy functions with complex innards, I'd sparingly add some type annotations to maintain my sanity

True. Python is like a beach that topless is allowed. Some people just don’t feel secure without it.

I think it’s a respectable view on it. And I think most people will probably also disagree with my: banana: Fruit = Fruit() But that’s now a huge habit of mine. Even if it looks redundant, I enjoy having it because it feels even extra explicit in my mind. I think what you said makes sense though!

the problem is when you reuse a variable, without knowing. the changed type can give you a warning

Even in C++ I'd write "auto banana = Fruit()" in that case and not write the type name twice.

I will get to them next year, any recommendations for topics you'd like to see?

@@Indently Well, map() function in both JS & Python is my instance problem, even though it should be so simple, I just need to convert a huge list with 3 to 4 levels deep nested lists, only need a list from only one element. Also, please don't forget about the banana, he is our favorite friend 🍌

I will keep it in mind! I never forget about banana 😉

Try a static type checker like mypy

It's not quite what you're talking about, but check out pydantic. It allows you to create data models and allows some type enforcement.

Look at mypy if that's what you are looking for. I would say though that enforcing restrictions on everything is not very useful and could easily limit your options and make your code worse, since it takes a lot of effort to annotate everything correctly, maintain that and not put unnecessary restrictions that prevents you from reusing your code. Personally I tend to annotate public interfaces as much as it looks reasonable, but not internals. I found that if your code is structured well enough, you normally should be able to comprehend what's going on in short functions without spending time on maintaining type hints for them. Also keep in mind that linters could use not just explicit annotations, but could also infer possible type from the code itself. So if you write something like. x = 1 if cond else "1", then linter after consuming this line would infer that x could be an int or a str and use this information later.

should try pyre-checker

I currently write in what I call "Python 2+" ... working on a system with both py2 and py3, I write in such a way, the code will work in either. (2.7 and 3.11)

​@@josephgaviotabut that's just... old python lol

@@gerardonavarro3400 Yes, but one has to work with what one has.

Grazie bello :)

Typython

I love PyCharm

That's me miss-typing on my keyboard actually ahahaha

@@Indently i also keep typing greek everywhere by accident. my keyboard layout switching shortcut is a bit too convenient.

@@chri-k European keyboards are a pain for coding ahahah.

Python doesn’t support overloading as far as I remember

@@Indently Not exactly. Overload is possible via functools.singledispatch decorator and it uses typehints to distinguish, which implementation to call. Typehints are not enforced in any way by language itself (unless you use something like mypy instead of regular cpython to run scripts, but that's a different story). However nothing prevents your code from reading function annotations and do some magic around them. That's exactly what singledispatch does, so it's rather a syntax sugar than a feature of language itself.

sure, you can

There is no compiler in python, it has an interpreter.

Thanks for the suggestion!

It's part of Python, you can do it everywhere

Good on you mate.

Do you know where I can find the docs for this?

Guido, Python creator, and other maintainers have said there are no plans for this as it goes against pythons core values.

That's what I thought as well, but maybe Aman has some article that we don't know about that he is willing to share with us.

@@Indently have you heard Guido on the lex Fridman podcast? If not, highly recommend. He was on twice, the most recent one was stellar.

Thanks for the recommendation! I've never heard of it no, I will check it out though.

Apparently it can if you look into some called "mypyc"

@Indently Thank you, I will definitely look into that right away.

That's the return type (the type of the value returned from the function). If you don't specify it, it would mean that your function returns None (or anything else really, as Indently said, type hints in Python are completely optional and not checked by cpython at all). If you mean why does his -> look like a real arrow, that's probably down to his IDE configuration, or eventually the font he's using (some specialized fonts use ligatures to make common code combination like -> or

Do you mean PEP? Or is there something with PHP that I’m missing?

@@Indently PHP, the programming language, competitor to Python on the web, but not so much on data crunching

Excuse my ignorance, I'm not really familiar with PHP so I thought you meant PEP ahah.

@@Indently No worries. I figured as much. I don't know much more than what I shared about PHP bytecode generation anyway. I figure Python will get there too at some point.

If you every used a language that is statically typed before, it's very easy to make this mistake in Python if you're new to it.

I thought that

I like to think of Python as a free language. It lets you do what you want, even if what you want isn't always what you want ahah. They shouldn't require it in vanilla Python, but possibly provide us an option for enabling that, such as a special import, or with a special version of Python that replicates TypeScript.

@@Indently type #@type=static... something like that.

That would be neat!

I can't believe you called me Idently, twice, Simon 😅

@@Indently hahahahaha didn't even notice

Typing does not determine the level of your language though. You have very high level languages that are typed (try Haskell) and you can do most low level stuff in any language (try embedded programming in Python, it sure is higher level than in C but you'll often find yourself sending binary codes to explicit pins on the board and so on) though that is not recommended for speed and memory control. Dynamic typing (types are attached to values, variables and functions don't have specific types, all typing is done at runtime) vs Static typing (variables and functions have specific types, which are decided at "compile" time) is more a matter of practical implementation and philosophy around programming. Note that some developers think they dislike static typing but they in fact lack experience with modern languages and confuse static typing with explicit typing (every variable/function type has to be explicitly written when they're declared) whereas almost all modern typed language can infer most types without specifying them in your code (even if the recommendation is generally to put type annotations at least on your top-level declarations, to get better error messages). Type inference is such a win that most traditional languages have been retrofitted with it in the last decade.