Python LAMBDA FUNCTION?! #python #programming #coding 

That made me understand this less. Why would you do that when you can just print(X+Y) or print(1+2)?

​@@MrWayneDXI think the video would've been better if it showed how it can be used when mapping over an array or something.

Damage is already done. U can recover you honour now. 😊

@@MrWayneDXYou wouldn't but there are a lot of other instances where it would be easier to define a function and use it all in one line instead of wasting 3 lines of code on it.

Ah, okay. How about a serious one, then?

​@Darth Vader and 3+1?

​​@Darth Vader No need. Already written my code and It says: 31

this is how i calculate 1+3 def add(x, y): sum=0 for i in range (x): sum+=1 for i in range (y): sum+=1 return sum print(add(1,3))

@@youber3200 that's so cool it worked! There might be a small efficiency problem though, so do you think it could manage 1+4?

@@youber3200 There are too few operations and lines of code, this can't work.

Haha why so? I’m new to programming

@@taiwo_the_illusive They're just significantly more difficult to read and understand if you're not used to them.

They're not hard to understand if they're used for what they're supposed to be used for, simple and short expressions that can be easily expressed in line.

I had to follow-up a guy that LOVED them. I swear every other line was a LAM

so do you really only use these in specific use cases, or just try and avoid them? Or is it just personal preference? Just out of curiosity of course, I'm in the networking field but I'm teaching myself to code.

It’s just easy bro

Max, min, and sorted as well.

Can you 'splain main

@@user-wr2cd1wy3b Both of the above functions, as well as min/max/sorted, take in an iterable (list, tuple...) and a function, and apply that function to each element of the iterable. map returns the result, while filter returns an iterable with the unchanged elements, but only those where the function returned True. As for min, max, and sorted, their optional "key" parameter applies the function to each element and then works with the resulting values instead of the original values. If you don't use lambda, you have to create a new function every time you want to use them. For example, if you want to sort a list of 2-tuples based on the 2nd element, you have to create a function def f(x): return x[1]. That wastes 2 lines, 4 if you comply with PEP8, just so you can write "key=f". If you use lambda, you can create that function in an "anonymous" way, meaning you don't give it a name or anything, it just does something simple. In this case, you could write "key=lambda x: x[1]" and you'd be done. Assigning a name to it is possible, you could write "f = lambda x: x[1]", but it's not recommended in most cases. This makes things so much more readable in functions, and makes them so much more powerful.

I agree my friend.

Your teacher is teaching you that because you will eventually need it. Lambda are essential to keep a clean code and improve readability. Any good programmer knows how and when to use lambdas.

@@philippebaillargeon5204 I know, I understand that now. I was just joking about my attitude back then. I understood how to write functions and recursive functions and even did it well but I was so hung up on thinking that Lambda was a waste of time and an insult to all the effort I put into everything that did the same thing. I'm a little more experienced and greatly more appreciative now

I'm mainly learning game development, so for me, lambda functions have been useful mostly for me in being able to pass a function that requires parameters in places where it's normally not allowed.

Lambdas in Python aren't great... you can actually assign them to variables, though: my_lambda = lambda x, y: x + y Then you can call it like any other function: my_lambda(1, 2) Most programming languages support multi-line lambdas and they're essential in functional programming. They're just anonymous functions that you don't need to declare and keep around, and if you have something like Kotlin, they are extremely powerful.

Hey I just started learning python too, do you have any advice about indentation? I get the basics of it but sometimes it gets confusing. Is there a rule or pattern?

@@originaljokester7679 The indentation in Python is absolutely required to delineate code blocks because there are no braces like other languages. Foe xample: if cash > 0: pirin('You do have cash!" else: print('Poor as dirt...." If you don't insert the indentitation (usually four, sometimes two if you want), then Python doesn't know how to process a block.

Why

@@dangdrjay3011because they don’t understand what the value of anonymous functions is and they have anger issues…

wow it makes sense ayo

So if I want to pass new inputs I have to define a new lambda line?

@@AJ.911 if you're going to be reusing it, then you probably want a named function and not an anonymous function.

Lambda is what they're called in Haskell and Java too.

in js, anonymous functions is something different

@@timber2leaseI’m pretty sure that Anonymous Function = Arrow Function (js) = Lambda (python) But there are probably some scoping differences here and there, idk

try to code lamda funcrion in other languages and you will understand why its so cool and easy to use. Unfortunatly python does not represent lambda fucntion like in other languges. In python its just boring and useless shit.

you still dont if you think this is how to use these

Just think of them as the simplest possible kind of function. Assign one to a variable (like any other value) and you have a small reusable function. Why do they exist? In Python, mostly just as "syntax sugar" - a concise way to write tiny functions. They aren't necessary. You could always define a normal function instead. But for tiny functions, it's nicer to have a tiny syntax to go along with them.

as someone not new to programming, yes he did

names = ['George', 'David', 'Sam', 'Rob'] names.sort(key=str.upper) Sorts by name in a case-insensitive manner. If you only want a partial sort based on the first letter of a given name, instead of the entire name, you can use a lambda that returns the first letter, optionally applying str.upper() to that letter: names.sort(key=lambda s: s[0].upper()) Lambda in Python is intended to be used for that kind of thing - a short, uncomplicated function you only need for one particular use case. You might use it to sort even numbers before odd numbers for whatever reason: nums = list(range(10)) nums.sort(key=lambda n: n%2) The demo was a bad example, intended to illustrate that it's the same as a function, forgetting to illustrate why you might prefer it over a named function in the first place.

I use lambda frequently when providing the “key” keyword argument of sorted() or list.sort(). Sure, you could define a function specifically for a special sort, but if you know you will only ever use it on one line of code, you might as well keep that sorting logic all on one line of code.

he is showing things in useless cases to make it easier to explain, you when you are writing code you will need to know how to use the things you learn in a useful way

@@GuizinPE81 yeah mate, reason why I wrote that comment 💪🏽💪🏽💪🏽

@@JordanMetroidManiac in a dict for example ? Can you be more specific ? (I’m a noob over here hahaha)

but what's the fun in that?

I am fairly new to lambda functions after having coded for around 47 years. They're...cute.

Just think of it as an anonymous, unnamed one line function.

@@vorpal22 Well, I don't tend to use those in my code yet, so that explanation still wouldn't have helped me in the past.

it’s very useful actually