iter clear solution for All the Same by veky - python coding challenges

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iter solution in Clear category for All the Same by veky

def all_the_same(elements):
    el = iter(elements)
    first = next(el, None)
    return all(element == first for element in el)

Jan. 30, 2018

Comments:

lsdda on Dec. 5, 2018, 7:18 a.m.
Good use of the iterator protocol.

silvyan on June 12, 2019, 4:16 p.m.
another way to use an iterator : <pre class='brush: python'>def all_the_same(elements: List[Any]) -> bool: return all(elements[0] == elt for elt in elements[1:]) </pre>

veky on June 12, 2019, 9:38 p.m.
That's not really an iterator but a generator, but more importantly, it requires elements to be a sequence. In my solution, the argument itself can be an iterator.

jcfernandez on June 19, 2019, 1:38 a.m.
Since the precondition for this mission states that are elements are hashables, wouldn't be simpler to just convert the list into a set and return its length ? Like this ``` def allthesame(elements: List[Any]) -> bool: return len(set(elements)) <= 1 ``` Is it better to work with iterator or generators rather than using a set for this case ?

veky on June 19, 2019, 8:20 a.m.
To be honest, I think that precondition was added after I already solved the task. But there is one more thing to consider, why my solution is better: imagine `allthesame(range(10**7))`. My implementation finishes very quickly, yours must build a set of ten million elements. (Of course, the whole point of CiO is to show various approaches to the solution. "simple" vs "efficient" is a frequent tradeoff, but there are others.)

jcfernandez on June 19, 2019, 5:02 p.m.
You're right, it takes a lot more of time to finish when you use a set(...), I always thought that sets in python were very fast, now I know that its creation can be slow. Also, it seems that range(...) by itself woks as a generator, can you please put some documentation about the resource consumption, on sets, list, tuples, ranges and so on.

veky on June 19, 2019, 8:53 p.m.
"Sets are very fast" means nothing by itself. Data structures aren't fast, operations on them are. Python lists have very fast random access, but very slow insertion at beginning. Deques are the other way around. In the same way, "resource consumption" is meaningless. Some things take lot of space, other things take lot of time. Yet other things consume various other resources of the system. (I suppose you meant time. Then the best you can get is probably <a href="https://wiki.python.org/moin/TimeComplexity">https://wiki.python.org/moin/TimeComplexity</a> .) And no, range is not a generator, but if you just meant to say that it doesn't separate its elements spatially (but temporally), you're right.

Ivan_Khimich on Aug. 25, 2019, 9:14 p.m.
Unfortunately it's not correct. Test your function with argument like <pre class='brush: python'>all_the_same([True, 1]) # True </pre> Function returned True, but it's not correct.

veky on Aug. 26, 2019, 3:20 a.m.
Depends on your meaning of "correct". :-) The mission text says: <blockquote> check if all elements in the given list are equal. </blockquote> Do you agree that True is equal to 1? Maybe another example will help: what do you think about allthesame([0, 0.0, -0.0, 0j])? :-D Yes, the mission title, and the name of the function, suggests a different interpretation (which can just be realized by replacing `==` with `is` in my solution), but I still think the text should have priority of interpretation.

bsquare on Sept. 18, 2019, 9:12 a.m.
Interesting solution :)

thz on Dec. 8, 2021, 9:51 a.m.
+Ok, it's clear. +Ok, it's speedy. +Ok, it's creative.

veky on Dec. 8, 2021, 9:53 a.m.
In the sense that it returns False as soon as it finds an element that's not the "same" as previous ones, yes, but otherwise, not particularly. :-)

thz on Dec. 8, 2021, 10:41 a.m.
I'm just on a mission "Find and review specific solution" :)). But really, I like your solutions (for other tasks too).

veky on Dec. 8, 2021, 10:43 a.m.
Yes, I know, these missions are stupid, but I realize you want the points. :-)

Aleksandr_Kazakov on April 11, 2023, 5:34 p.m.
Find and review specific solution

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