hi guys, something's driving me absolutely insane

I'm trying to use PropertyValue to set the EdgeWeights of a graph

so I have some graph x, and I do PropertyValue[x,EdgeWeight]={1,5,9}

(x only has 3 edges)

But when I evaluate x after that, it's the same as it was before

SetProperty doesn't work either

Oh god, I'm an idiot...

Nope, never mind, this is still insane

I have no idea what could be wrong, I'm doing it exactly like people online

Ok I'm starting to think something's messed up with SetProperty

Does mathematica have a no-op function? Like ":" in bash and "pass" in python.

@shrx I think Null is about as close as you get, but every expression evaluates to an expression. And everything is an expression. I'm not really sure what a no-op would be in M. There's also Sequence, as in List[2, 3, Sequence[], 5], which from a certain point of view could be considered a no-op. Usually, I just insert a Null if I don't want to look at a colored comma.

@MichaelE2 yep, I usually use Null too for this purpose. Do you think this is worthy of a proper question on the main site?

@shrx It would get more attention than in chat. Also, it might help new users coming from other languages. On the other hand, experienced users might think it too basic. You might wait and see if anyone else chimes in. I would think it is worthy, but I probably wouldn't answer. Others are better versed in CS language theory.

@shrx I can't really think of a case where a no-op would be unavoidable. Do you have a good example?

@SjoerdC.deVries Dolce far niente. :)

It's also the epitome of (American) workplace ethics: How to appear busy while doing nothing...

@SjoerdC.deVries not really, I just thought about it while doing something in python

@MichaelE2 I learned that from the Dilbert comics

dilbert.com/strip/2013-03-24

dilbert.com/strip/2009-10-04

dilbert.com/strip/2002-06-16

dilbert.com/strip/2001-11-04

dilbert.com/strip/1997-04-27

Arcade plane shooter:

community.wolfram.com/groups/-/m/t/493540

Have anyone got this error?

I downloaded the new Mathematica installer from user portal but it is blocked by the OS.

A lot of no-effort questions once more

Gimme da codez... oh dear.

what is the cool way to see if a list contains all elements of another?

@MarianoSuárez-Alvarez I don't know about cool but Length@Intersection[list1, list2] == Length@list1 implies that list1 contains all elements in list2.

SubsetQ?

that's what I do, or And@@(MemberQ[xs, #]& /@ ys), but both feel like I am missing a standard function :-|

Also, how does one read in a package but not letting it pollute the global context?

@chuy that's it

@chuy that exists?

yes

well since version 10

Ah. I'm trapped in 9.0

Length[Complement[list1, list2]] == 0 might work