Recursion in Python  

Yeah didn't know that

Good 'ol fprintf

You can also specify a separator with the sep keyword argument which is default to " " (space) x = 1 y = 2 print(x, y) # prints: 1 2 print(x, y, sep=",") # prints: 1,2

2

Same here 😅

But "else" does make the code more readable

Heck, use a walrus operator or just open the file beforehand and close after

@@calliioa And then you lose the 30% of persons using python 3.6

@@ItalianPizza64 That's true but so does an extrawhitespace, which is what I would do

True, but I like readable code, so i use it.

Or use Haskell in which it's actually more performant to write in the recursive form

Video example plz.

@@WilcoVerhoef it's like first telling how a molecule works, and then a whale.

Would it be something like this? (i'm learning Python so feedback would be great) def factorial(n): acc, x = 1, 1 def step(): nonlocal acc, x acc *= x x += 1 return acc res = 1 for i in range(n): res = step() return res

yeah that code looks good. Theres no need to change it but one of the advantages however of writing your code using closure is that you can continue the function from whereever you leave off so maybe its not ideal to put the for loop inside of the outer function. def factorial(): acc, x = 1, 1 def step(): nonlocal acc, x acc *= x x += 1 return acc return step fact = factorial() for i in range(1,5): num = fact() print(i, num) try this one out, because the foor loop is outside of the function you can pick up where it leaves off by calling fact() again this way you can use your function to calculate 100! and then if you decide you can immediately start calculating 101! without having to start at 1 again

from functools import cache @cache def fib(nth): if nth < 2: return nth return fib(nth-1) + fib(nth - 2)

Why?

@@dfla5472 because factorial 0 give you the value of 1. If you do n == 1, factorial 0 will give you error instead of returning 1.

@@glooring7039 that's not the point. The point is that 0! equals 1, but this function can't evaluate the factorial of 0

@@soewaiyanaung why when n is 1 the control will move to the if block and simply return 1

@@geniusvedant673dude if you give it the value 0 it won't return 1 ever! Because 0 isn't 1 and better: the next number in this code would be -1 and it will go on until the stack is full and this will lead to a stackoverflow. Try it yourself. The if should be if n == 0 or if n == 0 || n ==1. The second one would return the factorial of 1 even without recursion.

integer limit tho :((

@@willardsun5437 Try to write your own big integer, if you are worthy.

Rust has recursion limit no ?

Isn't this already linear time?

cache seems like a waste of memory for a factorial function……… just saying that shit is gonna fill up fast

@@caedenw classic memory/speed tradeoff, as an educational example, it should have it, in real use you need more checks and limits ofc

@@AlexanderBukh not really… why would you memoize something you never use as a recursive call? the recursive DAG for this has a trivial topological sorting which is just in order from 1 to n so there is no point in using a cache decorator. the recursive calls are literally never reused. plus now you have to store in memory a bunch of large numbers. that means memory must be allocated for this purpose which takes time so a cache decorator would be slower. but if you ever want to computer the factorial more than once, sure it would be a speed up to have precalculated this. i would personally prefer to store the precalculations in a list, but whatever floats your boat. i still think there are better ways because the memory requirements become huge even for relatively small n.

@@chrisisawesomeandcoo he meant constant

in the first definition you're making an unnecessary function call with n = 0

python is garbo

@@kadensharpin2156 it's quite slow, but it's very readable and it's more of a glue language: use easy-to-read stuff to outsource hard tasks to other languages like C (import numpy). also you can do things quick and dirty, like if you just want, idk, a truth table for a boolean function, easier to write a few Python lines than C++, for example. I'm learning C++ and Python, so I think I can see the difference

@@no-better-name honestly I'm just trying to bait. I have never used python before and frankly I don't think I ever will. However, Python does have a lot of valid uses. IMO the archaic syntax and no types throws me off. For me, typescript or java is easiest to write something quick and dirty because these languages follow the common programming syntax.

@@kadensharpin2156 ... master baiter **badum-tss**

What about (1/2)! ?

@@alibinnaseer bro that will be sqrt(pi) it won't come under normal factorial rules

what about factorial("meow") ?????

@@catlord69 hah xd

@@maheedhara4317 man, gamma function is weird i tried plugging in some numbers and well, apparently error function is a thing. really interesting and entertaining

What

@@carbun. basically, because it only checks if it is equal to one(which is what it would be equal to on the last step of recursion for positive integers), 0 or lower will never satisfy the condition meaning it will keep calling the function until it errors

factorial(0) = 1 fyi

@@laenprogrammation supposed to be, they didn't define it though

Нет, он все правильно написал

Числа Фибоначчи

не более секунды

Если там не больше 50 коллов, то не думаю, что это проблема. Например в квиксорте

What do you mean? If you talking about syntax highlighting, it's a "PyCharm".

Thats roughly how all JetBrains IDEs look. Syntax highlighting though is supported throughout all IDEs and even some text editors. Just search up Python IDE and choose by preference or simply download PyCharm Community Edition for a safe bet.

2000!

2000!

You don’t need recursion to do anything but sometimes it’s better to use recursion

pyCharm повсеместный стандарт)

I think it is “JetBrains Mono”.

I like this use of the translator. You can see it right away, but it's interesting when this happens.

I believe it is PyCharm

A new file.

It'll hit RecursionError

it would be better to write the if-statement as if n == 0 or n == 1: return 1

0! = 1

It didn't have a limit unless you put n-1.. When a function call its self its called recursion. Well, the function is gonna call its self until the value of n = 1.. And everytime is trigger it will decrease by 1 from the initial value. This is a good practice but loop is faster.. But recursion is great for finding value

@@yousufhossain9768 I know what recursion is but the question is why does a limit for it exist in Python Stack trace issues?

@@IlliterateSorcerer maybe he set a limit for safety.. But it never required from first places .

@@yousufhossain9768 No he states that the default is 1000. Fuuuuck this I'll just stick to c++

@@IlliterateSorcerer Because why not? People can make a mistake. Without a safeguard like that, a simple mistake could crash the whole system.

It is very unlikely considering the recursion depth is only 2002 and the max integer has < 2002*3 digits.

You clearly dont know how to use a keyboard my guy

@@FabioGamingFG lmao

похуй

хз очень странно

Найс рофл