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

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  • Опубликовано: 23 дек 2024

Комментарии • 57

  • @aflous
    @aflous Год назад +62

    "as _" ? Why the h*** would you ever do that? Just delete those 4 extra characters from you code

    • @thegothaur
      @thegothaur 10 месяцев назад

      it's used by django's translate engine

  • @ilcp331
    @ilcp331 Год назад +14

    My Mom: What should we name him?
    My Dad: Name him "_", we do not care about him

    • @shreyasj6437
      @shreyasj6437 9 месяцев назад +1

      In C# it is literally called the discard character

  • @callbettersaul
    @callbettersaul Год назад +38

    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  Год назад +12

      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 7 месяцев назад

      ​@@Indently well, if one wants to suppress it, with contextlib.suppress() is a much cleaner option

  • @MetaaR
    @MetaaR 9 месяцев назад +2

    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")

    • @Nbrother1234
      @Nbrother1234 8 месяцев назад

      Here, _ is a wildcard that never fails to match. If none of the other cases match, it will match with case _.

  • @Sinke_100
    @Sinke_100 Год назад +9

    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 👍🏻

  • @oida10000
    @oida10000 Год назад +3

    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 Год назад +1

      match case is pattern matching, you're using type(int()) you should just use int()

    • @schlopping
      @schlopping Год назад

      Is that not just a naming convention? Doing `case unused_variable:` would do the same thing

    • @sangchoo1201
      @sangchoo1201 Год назад

      just
      case int:
      doesn't work..?

    • @schlopping
      @schlopping Год назад

      @@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 Год назад

      @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)

  • @t.e.k.profitstraders8796
    @t.e.k.profitstraders8796 9 месяцев назад

    I think some of it was refreshing, duunder methods, however there were pretty neat tricks there!! We'll certainly be back again!!

  • @intron9
    @intron9 9 месяцев назад

    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 .

  • @garybigden810
    @garybigden810 Год назад +8

    Great presentation style and hugely memorable content! Thanks Buddy.

  • @DamjanDimitrioski
    @DamjanDimitrioski 8 месяцев назад

    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.

  • @lukerichards22
    @lukerichards22 Год назад +2

    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?

  • @loverboykimi
    @loverboykimi Год назад

    Thats very good. Looking forward to dunder methods of class video.

  • @HorridModz
    @HorridModz Год назад +2

    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  Год назад +2

      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.

    • @Jason-b9t
      @Jason-b9t Год назад +4

      @@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 Год назад

      ​@@Jason-b9t 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)

  • @finnthirud
    @finnthirud Год назад

    I enjoy your videos with your personal touch.

  • @samadshaik
    @samadshaik Год назад +1

    what IDE do you use??

  • @mastermanhwas
    @mastermanhwas Год назад

    How can we connect Cypress to python in pycharm? Can you please tell me

  • @alexislayton2150
    @alexislayton2150 Год назад +1

    Why does this video not mention the important role _ plays is match patterns?

    • @Indently
      @Indently  Год назад +3

      Because I absolutely forgot about it until you mentioned it! damn, it will be for the next one

    • @yoverale
      @yoverale 9 месяцев назад

      @@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!

  • @murphygreen8484
    @murphygreen8484 Год назад

    Unimportant exceptions was a new one for me!

  • @gavintillman1884
    @gavintillman1884 Год назад

    I’ve come across both * and _ in an unpacking context, but never *_ together. Is that quite new?

    • @Indently
      @Indently  Год назад +1

      It's been around for as long as I can remember :)

    • @ali-g
      @ali-g Год назад +1

      "*" usually means all so you are unpackaging all the in between values to "_"

    • @gavintillman1884
      @gavintillman1884 Год назад +3

      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 Год назад

      @@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.

  • @mayorc
    @mayorc Год назад

    Some are pretty useful.

  • @mhm6421
    @mhm6421 Год назад +2

    Everyone asks what is an underscore but no one asks how is the underscore...

  • @luissantos975
    @luissantos975 Год назад

    Wonderfull!

  • @daggerhound1395
    @daggerhound1395 Год назад +3

    U could do user._User__get_id() at 6:35 if any1 was curious

  • @sangchoo1201
    @sangchoo1201 Год назад +2

    _ is just a variable name.
    with a context of "I don't use it"

    • @eitantal726
      @eitantal726 9 месяцев назад

      Not exactly. open python console, type '10', enter. Then type '_' , enter. you'll see 10. More than "just a variable name"

    • @sangchoo1201
      @sangchoo1201 9 месяцев назад

      @@eitantal726 but it's still just a variable name, although the referenced variable is a special variable

    • @eitantal726
      @eitantal726 9 месяцев назад

      @@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 9 месяцев назад

      @@eitantal726 but _ IS a variable name, isn't it?
      what is a variable name:
      sangchoo1201
      _
      input
      what is NOT a variable name:
      if
      @#$
      1a

  • @rishiraj2548
    @rishiraj2548 Год назад +1

    Thanks

  • @lukerichards22
    @lukerichards22 Год назад

    Why use __str__() instead of __repr__()?

    • @sangchoo1201
      @sangchoo1201 Год назад +1

      __str__ is to convert the instance to a string
      __repr__ is to represent the state of an instance (more close to debugging stuff)

  • @HononoSNK
    @HononoSNK Год назад

    Basically, underscore is just variable name or simple letter. Nothing special. In can be replaced with any other letter.

  • @aimanshaa
    @aimanshaa Год назад

    Update you IDE