10 Ways You Can Use "_" In Python (Do you know ALL of them?)

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Indently

Indently

Күн бұрын

Пікірлер: 57
@aflous
@aflous Жыл бұрын
"as _" ? Why the h*** would you ever do that? Just delete those 4 extra characters from you code
@thegothaur
@thegothaur 6 ай бұрын
it's used by django's translate engine
@ilcp331
@ilcp331 Жыл бұрын
My Mom: What should we name him? My Dad: Name him "_", we do not care about him
@shreyasj6437
@shreyasj6437 6 ай бұрын
In C# it is literally called the discard character
@callbettersaul
@callbettersaul Жыл бұрын
2:32 But if you don't need to use the exception, why even write "as _" instead of leaving it to be "except ZeroDivisionError:"?
@Indently
@Indently Жыл бұрын
From what I read and saw, some people use it to explicitly show that they are ignoring it, but it is probably a very rare use case.
@vinylSummer
@vinylSummer 4 ай бұрын
​@@Indently well, if one wants to suppress it, with contextlib.suppress() is a much cleaner option
@Sinke_100
@Sinke_100 Жыл бұрын
In try except if you need to use _ you don't need it in the first place, just try except without variable output. Otherwise, great video man, this one was useful and informative 👍🏻
@garybigden810
@garybigden810 Жыл бұрын
Great presentation style and hugely memorable content! Thanks Buddy.
@MetaaR
@MetaaR 5 ай бұрын
You forgot about 'case _:' in a match expression. Example: n = int(input()) match n: case 1: print("n is 1") case 2: print("n is 2 times more than 1") case 3: print("n is bigger than 1") case _: print("n is weird")
@user-iy6dt4xp5o
@user-iy6dt4xp5o 5 ай бұрын
Here, _ is a wildcard that never fails to match. If none of the other cases match, it will match with case _.
@t.e.k.profitstraders8796
@t.e.k.profitstraders8796 5 ай бұрын
I think some of it was refreshing, duunder methods, however there were pretty neat tricks there!! We'll certainly be back again!!
@oida10000
@oida10000 Жыл бұрын
To point 4, it is also default case in the new match structure (3.10 and up). match type(myvariable): case type(int()): do_int_staff(myvariable) case type(float()): do_float_stuff(myvariable) case type(str()): do_string_stuff(myvariable) case _: print(f"Unsupported type {_}") Update: someone explains to me why this code throws an error in line case type(int()) but print(type(int())) works as expected.
@thomaseb97
@thomaseb97 Жыл бұрын
match case is pattern matching, you're using type(int()) you should just use int()
@schlopping
@schlopping Жыл бұрын
Is that not just a naming convention? Doing `case unused_variable:` would do the same thing
@sangchoo1201
@sangchoo1201 Жыл бұрын
just case int: doesn't work..?
@schlopping
@schlopping Жыл бұрын
@@sangchoo1201 case int: would compare it to literally the int type, instead of checking if its an instance of int or not. its supposed to be case int():
@sangchoo1201
@sangchoo1201 Жыл бұрын
@schloppppdev3002 1. match type(myvariable): wants to check the variable's type 2. match int(): is actually checking the variable matchs 0 (because default constructor of int creates 0)
@DamjanDimitrioski
@DamjanDimitrioski 5 ай бұрын
Can you cover setting _ (underscore) instead of method parameters in the signature some method/function? Uses cases: the IDE or linter complains the parameter is not used, but you don't need it and the specification states you must put it there, and also it doesn't support optional params and other neat features and it's in args section so no kwargs will work.
@loverboykimi
@loverboykimi Жыл бұрын
Thats very good. Looking forward to dunder methods of class video.
@intron9
@intron9 6 ай бұрын
6:48 a more common reserved name that would be wanted to use it for something else is "id" , it let's you reassign it though, but it's not recommended .
@lukerichards22
@lukerichards22 Жыл бұрын
What's the benefit to using it in exception handling, when you don't need to catch what the exception is at all if you're not gonna use it? Am I missing anything?
@finnthirud
@finnthirud Жыл бұрын
I enjoy your videos with your personal touch.
@daggerhound1395
@daggerhound1395 Жыл бұрын
U could do user._User__get_id() at 6:35 if any1 was curious
@HorridModz
@HorridModz Жыл бұрын
For 7 (Private) and 8 (Protected) - 4:16-6:40, I believe you are mistaken. AFAIK, both protected and private methods use a single underscore by convention, and name mangling with double underscore is not correct. Though both are common, I believe name mangling is incorrect. I don't know how to verify this, though.
@Indently
@Indently Жыл бұрын
I don't know where you're getting your information from. What I shared is a very common convention in Python, if you want to learn more about name mangling, check out mCoding, he made a proper video on it. Otherwise if you have resources that prove otherwise, I wouldn't mind looking at them.
@user-vt9bp2ei1w
@user-vt9bp2ei1w Жыл бұрын
@@Indently The name mangling is to avoid subclasses accidentally overriding parent class methods when inheriting. This behavior is documented in the wiki (and pep-0008): "Python's runtime does not restrict access to such attributes, the mangling only prevents name collisions if a derived class defines an attribute with the same name."
@ommahajan1
@ommahajan1 Жыл бұрын
​@@user-vt9bp2ei1w Yes I agree, the function does not become private neither it becomes difficult to find its name. I tried this by creating a sample class with a double underscore leading function. Then I passed in the object created by that function in dir() global function which had the function inside my class named as: '_ClassName__functionName'. According to PEP 8 : __double_leading_underscore: when naming a class attribute, invokes name mangling (inside class FooBar, __boo becomes _FooBar__boo)
@murphygreen8484
@murphygreen8484 Жыл бұрын
Unimportant exceptions was a new one for me!
@mayorc
@mayorc Жыл бұрын
Some are pretty useful.
@rishiraj2548
@rishiraj2548 Жыл бұрын
Thanks
@DealazonDaily
@DealazonDaily Жыл бұрын
How can we connect Cypress to python in pycharm? Can you please tell me
@alexislayton2150
@alexislayton2150 Жыл бұрын
Why does this video not mention the important role _ plays is match patterns?
@Indently
@Indently Жыл бұрын
Because I absolutely forgot about it until you mentioned it! damn, it will be for the next one
@yoverale
@yoverale 5 ай бұрын
@@Indently you forgot to mention one another common use you are even using in the video, defining __init__ method for classes 7:53 anyway great video as usual!
@luissantos975
@luissantos975 Жыл бұрын
Wonderfull!
@mhm6421
@mhm6421 Жыл бұрын
Everyone asks what is an underscore but no one asks how is the underscore...
@Indently
@Indently Жыл бұрын
That is very True
@HononoSNK
@HononoSNK Жыл бұрын
Basically, underscore is just variable name or simple letter. Nothing special. In can be replaced with any other letter.
@samadshaik
@samadshaik Жыл бұрын
what IDE do you use??
@sangchoo1201
@sangchoo1201 Жыл бұрын
it's pycharm
@sangchoo1201
@sangchoo1201 Жыл бұрын
_ is just a variable name. with a context of "I don't use it"
@eitantal726
@eitantal726 6 ай бұрын
Not exactly. open python console, type '10', enter. Then type '_' , enter. you'll see 10. More than "just a variable name"
@sangchoo1201
@sangchoo1201 6 ай бұрын
@@eitantal726 but it's still just a variable name, although the referenced variable is a special variable
@eitantal726
@eitantal726 6 ай бұрын
@@sangchoo1201 no, "Eitan" is just a variable name. when I type 10 and Eitan, I don't see 10. _ is different. I see it as "ANS" of the calculator
@sangchoo1201
@sangchoo1201 6 ай бұрын
@@eitantal726 but _ IS a variable name, isn't it? what is a variable name: sangchoo1201 _ input what is NOT a variable name: if @#$ 1a
@gavintillman1884
@gavintillman1884 Жыл бұрын
I’ve come across both * and _ in an unpacking context, but never *_ together. Is that quite new?
@Indently
@Indently Жыл бұрын
It's been around for as long as I can remember :)
@ali-g
@ali-g Жыл бұрын
"*" usually means all so you are unpackaging all the in between values to "_"
@gavintillman1884
@gavintillman1884 Жыл бұрын
I’m overanalysing it. It’s just treating _ as a variable and doing the usual * unpacking. So *_ isn’t a Python symbol, it’s just the * unpacking operator applied to variable _. The whole _ is just a convention that it’s ignored, syntactically (outside of console mode) it’s just another variable - right?
@ali-g
@ali-g Жыл бұрын
@@gavintillman1884 Yes exactly, if you want you can even use emojis instead of _. "*" operator changes it's behaviour if it's in between int or float data types; acts as a multiplier. If left side is a string and right side is an int, acts as a repeater. I think these two the most common ones.
@lukerichards22
@lukerichards22 Жыл бұрын
Why use __str__() instead of __repr__()?
@sangchoo1201
@sangchoo1201 Жыл бұрын
__str__ is to convert the instance to a string __repr__ is to represent the state of an instance (more close to debugging stuff)
@aimanshaa
@aimanshaa Жыл бұрын
Update you IDE
@kaninchengaming-inactive-6529
@kaninchengaming-inactive-6529 Жыл бұрын
Update you grammar
@qwerty_qwerty
@qwerty_qwerty Жыл бұрын
@@kaninchengaming-inactive-6529 but you used the same bad grammar as he did
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