The BIGGEST Misconception About Type Hints In Python Explained

  Рет қаралды 49,347

Indently

Indently

Күн бұрын

Throughout the web I've noticed a lot of people that have been using type hints thinking that it will achieve what "compiled languages" get in terms of static type checking and performance boosts. This video aims to try to address that misconception, and also gives a light introduction to how to actually use type hints in Python.
▶ Become job-ready with Python:
www.indently.io
▶ Follow me on Instagram:
/ indentlyreels

Пікірлер: 115
@lucky13pjn
@lucky13pjn Жыл бұрын
For those of us coming from strongly typed languages, type hinting is a nice little security blanket.
@evlezzz
@evlezzz Жыл бұрын
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.
@ZeroSleap
@ZeroSleap Жыл бұрын
@@evlezzz Oh interesting. So what the commenter ment is more the Static Typing part?
@mattizzle81
@mattizzle81 Жыл бұрын
I mostly care about intellisense. Sometimes I even create “dummy” modules to import just with type information to allow intellisense to work.
@0DAYBROKER
@0DAYBROKER Жыл бұрын
@@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.
@0DAYBROKER
@0DAYBROKER Жыл бұрын
this can also help prevent import cycle errors
@r3d646
@r3d646 Жыл бұрын
Personally I only use type hints in function definitions because it helps with documentation. Not having to do that for every variable is like half the reason I’m using python in the first place 😅
@PanduPoluan
@PanduPoluan Жыл бұрын
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
@esphilee
@esphilee 4 ай бұрын
True. Python is like a beach that topless is allowed. Some people just don’t feel secure without it.
@JSDudeca
@JSDudeca 8 ай бұрын
It really helps with auto-completion when dealing with custom modules and classes. I have been leaning heavily on this of late.
@caiolaytynher5994
@caiolaytynher5994 Жыл бұрын
One thing that I do since type hints are ment to improve readability and IDE workflow is only using them if the type is not explicit, either for the user or the IDE, like return types after calling a function. This means that, for me, creating variables using the primitive data types or using the class constructor don't really need type hinting because it's obvious. For example: banana = Fruit() In this case, both the IDE and the user know that banana is a Fruit, so adding annotations wouldn't do anything or make your code just more verbose. That's my opinion though, what you guys think about it?
@Indently
@Indently Жыл бұрын
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!
@schwingedeshaehers
@schwingedeshaehers 4 ай бұрын
the problem is when you reuse a variable, without knowing. the changed type can give you a warning
@b4ttlemast0r
@b4ttlemast0r Ай бұрын
Even in C++ I'd write "auto banana = Fruit()" in that case and not write the type name twice.
@thomasricatte8287
@thomasricatte8287 Жыл бұрын
Thanks for the video! In my case, I am using type annotations super often (at least in all function definitions) + mark type hint warning as error in the IDE ; it saved a terrific number of hours (not to mention forcing myself to improve my interfaces).
@GeorgeNoiseless
@GeorgeNoiseless Жыл бұрын
And it's a good habit to have for when you have to learn\switch to strongly typed language. Learning something like TypeScript or Dart is so much easier if you practice sound typing in Python.
@leleemagnu6831
@leleemagnu6831 Жыл бұрын
Great video, truly loved it! More on the subject would be nice!
@AlFasGD
@AlFasGD Жыл бұрын
All developers that have been writing dynamic code for years have been snorting that copium, Python couldn't last too long without type hints, proving once again that dynamic programming is not to be worshipped. It's nice to have every now and then, but definitely not for full systems, without any sort of type information. Same reason why we also got TS on top of JS
@bozok1903
@bozok1903 Жыл бұрын
I like using type hints and return type in function definition. It makes reading the code , writing documentation and debugging easier.
@JT-mr3db
@JT-mr3db 9 ай бұрын
Type hints are wonderful for documentation, absolutely love this.
@DaryaIbrahim
@DaryaIbrahim Жыл бұрын
Your voice is sooooo relaxing man, love to hear you teach forever, please give some advanced topics as well, not all of us are beginners
@Indently
@Indently Жыл бұрын
I will get to them next year, any recommendations for topics you'd like to see?
@DaryaIbrahim
@DaryaIbrahim Жыл бұрын
@@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 🍌
@Indently
@Indently Жыл бұрын
I will keep it in mind! I never forget about banana 😉
@adiveler
@adiveler Жыл бұрын
It's also great adapting this habit if you are learning non-dynamic programming languages!
@porzo2964
@porzo2964 Жыл бұрын
had a good laugh at your int initialiser reaction :D:D
@KetilK
@KetilK Жыл бұрын
I sometimes wish there was a strict python debug mode that automatically asserted that your objects in fact conformed to your type hints at runtime. In my opinion, debugging python code in larger projects can be hard at times.
@preritdas6998
@preritdas6998 Жыл бұрын
Try a static type checker like mypy
@itsmeben604
@itsmeben604 Жыл бұрын
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.
@evlezzz
@evlezzz Жыл бұрын
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.
@JaiminBrahmbhatt
@JaiminBrahmbhatt Жыл бұрын
should try pyre-checker
@castlecodersltd
@castlecodersltd Жыл бұрын
Very interesting. Almost as interesting as Copenhagen, where I was over the weekend. Thank you. ☺
@fluffy-cat
@fluffy-cat Жыл бұрын
2:30 this will cause an error in python 3.8, and not just for typings, it will break the whole code, and the fix is: from typing import List and use it with capital L. Same with Dict and Tuple. Backwards compatibility makes life easier for people with low storage space / slow internet speed that already have dependencies installed with a lower python version.
@josephgaviota
@josephgaviota 4 ай бұрын
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)
@gerardonavarro3400
@gerardonavarro3400 16 күн бұрын
​@@josephgaviotabut that's just... old python lol
@josephgaviota
@josephgaviota 15 күн бұрын
@@gerardonavarro3400 Yes, but one has to work with what one has.
@lukaschumchal7797
@lukaschumchal7797 Жыл бұрын
You made my day. Thanks 🙏
@nilshamacher5064
@nilshamacher5064 Жыл бұрын
I also like those typehints, and I think you missed that they're helping also for overloading functions if I'm correct. Coming from C++ , I appreciate types anyway 😉
@Indently
@Indently Жыл бұрын
Python doesn’t support overloading as far as I remember
@evlezzz
@evlezzz Жыл бұрын
@@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.
@francescoferazza9341
@francescoferazza9341 Жыл бұрын
Love your stuff!
@Indently
@Indently Жыл бұрын
Grazie bello :)
@PanduPoluan
@PanduPoluan Жыл бұрын
Ahahaha the bleep, lol 😂 I love type hinting. It makes IDEs much more useful. And also makes me more disciplined in writing my code. Next video suggestion if you haven't: The amazing power of "for unpacking" 😎
@Indently
@Indently Жыл бұрын
Thanks for the suggestion!
@allo5668
@allo5668 Жыл бұрын
3:11 Guido has hinted that there are no current plans to use type hints to speed up the interpreter, but that it’s something they’re going to look into down the road (5, 10 years time). So it’s not crazy to think that the hint could speed up the code when it’s running one day
@Indently
@Indently Жыл бұрын
Typython
@josephgaviota
@josephgaviota 4 ай бұрын
Thank you for this video. I've seen these type hints in various videos, and wasn't sure what's the purpose, since in my tests (by copying things in vids) ... it seems to have no effect. And since I've been writing code in vi for 40+ years, these type hints don't seem to have any benefit to me. BUT, I _DO_ believe in good commenting, good variable names, and using plenty of """ Very explanatory doc strings with examples including Use Cases """ so I hope programmers that follow me, will not be mad at me.
@Andrumen01
@Andrumen01 Жыл бұрын
The "typing" module includes broader and slightly better options for "typehints".
@DrGreenGiant
@DrGreenGiant 4 ай бұрын
Worth mentioning that I've found type hinting plays very nicely with tools such as GitHub Copilot. This massively speeds up development. I do wonder if cPython or pypy interpreters, for example, have any optimisations, or might get some in the future, where type hints improve JIT compilation speeds.
@judithlee7989
@judithlee7989 Жыл бұрын
Even though vim does not give me any warning if I'm assigning values against the type hints, I find it very useful and handy when I'm tracing some code.
@alidev425
@alidev425 Жыл бұрын
thanks bro for your clarification'👍👍 ,btw what is your favorite IDE for python programming?
@Indently
@Indently Жыл бұрын
I love PyCharm
@georgioszampoukis1966
@georgioszampoukis1966 Жыл бұрын
I think one instance where it does check the hints is when cythonizing to produce .pyd files.
@MingwaiTam
@MingwaiTam 4 ай бұрын
I hope the type hints will be used to facilitate the just-in-time compilation. It looks so reasonable.
@rahevar3626
@rahevar3626 Жыл бұрын
At 2:42 why was there a pi and beta when you tried to write list[str] is that a option i can turn on
@Indently
@Indently Жыл бұрын
That's me miss-typing on my keyboard actually ahahaha
@chri-k
@chri-k Жыл бұрын
@@Indently i also keep typing greek everywhere by accident. my keyboard layout switching shortcut is a bit too convenient.
@Indently
@Indently Жыл бұрын
@@chri-k European keyboards are a pain for coding ahahah.
@hatdidog864
@hatdidog864 Жыл бұрын
can you make a video about the docstring, sir?
@Knud451
@Knud451 Жыл бұрын
Thanks! Maybe a n00b question, can you also specify the parameter and return type to be e.g. a dataframe?
@schwingedeshaehers
@schwingedeshaehers 4 ай бұрын
sure, you can
@mahdirasouli6005
@mahdirasouli6005 5 ай бұрын
Did you worked with mypyc?
@codingnovice
@codingnovice Жыл бұрын
Nice I would have just used ChatGPT! I've been learning that way. I share the stuff I build too.
@Indently
@Indently Жыл бұрын
Good on you mate.
@re.liable
@re.liable Жыл бұрын
With type hints, you help intellisense help you better :D
@calebparks8318
@calebparks8318 Жыл бұрын
Mypy has a compiler that should speed-up your code. I believe that type-hints are required.
@vhmolinar
@vhmolinar Жыл бұрын
Is it possible to tell the compiler to consider these type definitions?
@md.redwanhossain8822
@md.redwanhossain8822 Жыл бұрын
There is no compiler in python, it has an interpreter.
@insidious6068
@insidious6068 Жыл бұрын
Does this only work in PyCharm or can this work in something like VS Code?
@RedHair651
@RedHair651 3 ай бұрын
It's part of Python, you can do it everywhere
@AmansLab
@AmansLab Жыл бұрын
In Future releases of python this will be used in runtime. so, it is good practice
@Indently
@Indently Жыл бұрын
Do you know where I can find the docs for this?
@preritdas6998
@preritdas6998 Жыл бұрын
Guido, Python creator, and other maintainers have said there are no plans for this as it goes against pythons core values.
@Indently
@Indently Жыл бұрын
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.
@preritdas6998
@preritdas6998 Жыл бұрын
@@Indently have you heard Guido on the lex Fridman podcast? If not, highly recommend. He was on twice, the most recent one was stellar.
@Indently
@Indently Жыл бұрын
Thanks for the recommendation! I've never heard of it no, I will check it out though.
@qondonyon
@qondonyon Жыл бұрын
yep
@mattmess1221
@mattmess1221 3 ай бұрын
Type hints actually can speed up your code, but you have to compile it with mypyc.
@sg8nj
@sg8nj Жыл бұрын
I don't know what is the use of dynamically typed
@airatvaliullin8420
@airatvaliullin8420 Жыл бұрын
You can also run typecheckers
@sorvex9
@sorvex9 Жыл бұрын
What some people think type hinting does, JIT tracing actually will do.
@LegenDUS2
@LegenDUS2 Жыл бұрын
Explicit is better than implicit - Zen of python
@mikeg9b
@mikeg9b 3 ай бұрын
3:17 "...no type checking is occurring at run time." That doesn't sound right. Python always does type checking at run time, and type hints doesn't change that (because Python ignores them). That's one of the reasons Python is slow. On the other hand, in languages like Go and Rust, BECAUSE the type checking happens at compile time, there is no need for it at run time.
@ThankYouESM
@ThankYouESM 4 ай бұрын
Dang... I was hoping for it to optimize the performance.
@Indently
@Indently 4 ай бұрын
Apparently it can if you look into some called "mypyc"
@ThankYouESM
@ThankYouESM 4 ай бұрын
@Indently Thank you, I will definitely look into that right away.
@uplink-on-yt
@uplink-on-yt Жыл бұрын
Ah, it doesn't do what PHP 8 does, yet. It doesn't care about the type hints at compile time. PHP does generate more efficient bytecode when you use type annotations, and does do type checking - it's still opt-in, but it's now standard usage.
@Indently
@Indently Жыл бұрын
Do you mean PEP? Or is there something with PHP that I’m missing?
@uplink-on-yt
@uplink-on-yt Жыл бұрын
@@Indently PHP, the programming language, competitor to Python on the web, but not so much on data crunching
@Indently
@Indently Жыл бұрын
Excuse my ignorance, I'm not really familiar with PHP so I thought you meant PEP ahah.
@uplink-on-yt
@uplink-on-yt Жыл бұрын
@@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.
@bicycleninja1685
@bicycleninja1685 9 ай бұрын
Type hints does speed things up if you Cythonize the class
@lukekurlandski7653
@lukekurlandski7653 Жыл бұрын
Do people out there actually think that type annotations "speed up" your code? Seems like you'd actively have to avoid reading any documentation to have this misconception.
@Indently
@Indently Жыл бұрын
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.
@RedHair651
@RedHair651 3 ай бұрын
I thought that
@rondamon4408
@rondamon4408 4 ай бұрын
I thought it was just to make source code bigger
@vitu_9403
@vitu_9403 Жыл бұрын
ok, but what is that "->" ???
@chaddaifouche536
@chaddaifouche536 Жыл бұрын
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
@denizsincar29
@denizsincar29 Жыл бұрын
type hints must absolutely throw an exception if you mismatch types. let's go towards static typing, dynamic is an old tradition guys.
@Indently
@Indently Жыл бұрын
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.
@denizsincar29
@denizsincar29 Жыл бұрын
@@Indently type #@type=static... something like that.
@Indently
@Indently Жыл бұрын
That would be neat!
@IgorGuerrero
@IgorGuerrero Жыл бұрын
Please at least use them as arguments and return values... I do not use it in cases like variable declaration when the value assigned is static and easily resolved by the Python's LSP server.
@RetroGamingRandomness
@RetroGamingRandomness Жыл бұрын
Idently: Python is meant for simplicity, if you want something else just use a lower level language also Idently: uses typing that low level need to work anyway me: *confused thinking*
@Indently
@Indently Жыл бұрын
I can't believe you called me Idently, twice, Simon 😅
@RetroGamingRandomness
@RetroGamingRandomness Жыл бұрын
@@Indently hahahahaha didn't even notice
@chaddaifouche536
@chaddaifouche536 Жыл бұрын
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.
@KA3AHOBA94
@KA3AHOBA94 Жыл бұрын
__int__ lol haha
5 Good Python Habits
17:35
Indently
Рет қаралды 422 М.
How Many Balloons Does It Take To Fly?
00:18
MrBeast
Рет қаралды 47 МЛН
КАРМАНЧИК 2 СЕЗОН 7 СЕРИЯ ФИНАЛ
21:37
Inter Production
Рет қаралды 537 М.
LOVE LETTER - POPPY PLAYTIME CHAPTER 3 | GH'S ANIMATION
00:15
Python: A Quick Guide To Type Annotations (ft. Mypy)
11:25
Indently
Рет қаралды 28 М.
5 Reasons Why You Should Use Type Hints In Python
13:54
ArjanCodes
Рет қаралды 104 М.
How To Use List Comprehension In Python
6:41
Taylor's Software
Рет қаралды 6 М.
5 Useful Python Decorators (ft. Carberra)
14:34
Indently
Рет қаралды 91 М.
Python 3.12 release: The BIGGEST in 15 years
8:05
Carberra
Рет қаралды 48 М.
5 More Useful F-String Tricks In Python
9:38
Indently
Рет қаралды 44 М.
5 Really Cool Python Functions
19:58
Indently
Рет қаралды 56 М.
5 Tips To Write Better Python Functions
15:59
Indently
Рет қаралды 96 М.
How Many Balloons Does It Take To Fly?
00:18
MrBeast
Рет қаралды 47 МЛН