Iterate over all pairs of consecutive items in a list
Iterate a list as pair (current, next) in Python
Questions on the legal protection of games and their parts (assets, sounds, title) we started new pirate game, and I just want to ask some questions about rights. So I am new in game dev, I guess there are a lot of answers, but I guess professionals can advise something for first steps.  So we started some things like:   concept arts sounds we are working on the name of the game (just use temp one for now) we develop some models of ships and characters   I have question what's my step to protect everything I listed above. Do I need to protect everything separately? Do I need to register a game somewhere? Can I use my already made domain and subdomain for the game? Or do I need to register unique one domaine. Using mask as a garbage matte to hide an object I'm trying to use a mask to hide a part of a render layer, so that when the render layer is shown over a movie, some parts in the movie will appear to be in front of the render layer.  For example, assume I want to add a box to this image, so that it would look like it's behind the person:    I created the following simple object:    If I render the object, it looks great - the object is solid, everything else is transparent (I didn't use any 'sky'):     Now I create a mask to describe the standing person (or at least the part that would otherwise be covered by the box):    What I want now is to create a "hole" in the rendered box, so that when I use Alpha-over, the box look as if it's behind the person, but I can't find an easy way to do that. My first guess was to use 'Set alpha' to apply the mask (inverted) as an alpha for the rendered layer, but this doesn't look good:    The mask did create a "hole" where it should, but now all the other pixels are not transparent. How can I "retain" the transparent pixels while setting more pixels to be transparent based on the mask (use it as a matte)?  Note: I can do this with (I'm ashamed to say) some math work on the alpha channel, but it just doesn't seem right:    Thanks, and sorry for the [oh so] long question. I gave my friend  as a brainteaser; while her attempted solution didn't work, it raised an interesting question.  I flip a fair coin repeatedly and record the results.  I stop as soon as the number of heads is equal to twice the number of tails (for example, I will stop after seeing HHT or THTHHH or TTTHHHHHH).  What's the probability that I never stop?  I've tried to just compute the answer directly, but the terms got ugly pretty quickly.  I'm hoping for a hint towards a slick solution, but I will keep trying to brute force an answer in the meantime. Speed of light travel I have just started special theory of relativity. The limiting speed known as speed of light fascinated me most. I asked my teacher:      Consider two massless objects moving in the same direction at the speed of light. What would be their relative velocity w.r.t each other?   My teacher tells me that their relative velocity would be zero. But then the speed of light is universal constant regardless of the motion of its frame of reference, so shouldn't their relative velocity be $c$? What is their relative velocity and how? Do objects moving at the speed of light obey law of addition of velocities? Use a .jar java library API in C#? I'm an entry level programmer so please be descriptive in your responses.  I am trying to use a Java API given as a .jar file in my C# .net application.  I don't know much Java, but this .jar file says "no main-class manifest attribute" when I try to run it so this means its a library?  This Java API also comes with a .java file which shows how to use the library but I cannot see the code inside the .jar.  I found  on this site, and one of the answers reads, "In simple way you can pack your java classes to jar file then In C# use Process class for execute and map IO stream."  I am semi-familiar with the Process class in C# but I don't understand how I could use it to use a Java library in my C# .net project.  Is this possible? or was that answer incorrect?  If so, could you explain how I can use the .jar library in my C# app. I am looking for an application which can do the following:   Resize one or more images Compress images Rotate and flip images Rename multiple images using a progressive number or a prefix/suffix Convert an entire PDF file to a bunch images Extract an image from a Windows .ico file Convert images to DPX, EXR, GIF, JPEG, JPEG-2000, PDF, PhotoCD, PNG, Postscript, SVG, TIFF, and other formats   I am running Ubuntu GNOME 15.10 with GNOME 3.18. Why are only certain shutter speeds or apertures available? Is there a limit to a total number of months a holder of UK multiple entry visitor visa can spend in UK per calendar year? Creating fishnet grid Shapefile in QGIS? How do I create a fishnet shapefile using QGIS?   The equivalent task of "Create Fishnet" in ArcGIS. Delete all files except in a certain subdirectory with find I want to recursively delete all files not accessed in a while in folder a, except all files in the subfolder b.  find a \( -name b -prune \) -o -type f -delete   However, I get an error message:     find: The -delete action automatically turns on -depth, but -prune does   nothing when -depth is in effect.  If you want to carry on anyway,   just explicitly use the -depth option.   Adding -depth causes all files in b to be included, which must not happen.  Anyone know a safe way to make this work? Text processing - join every two lines with commas I have more than 1000 lines in a file. The file starts as follows (line numbers added):  Station Name Station Code A N DEV NAGAR ACND ABHAIPUR AHA ABOHAR ABS ABU ROAD ABR   I need to convert this to a file, with comma separated entries by joining every two lines. The final data should look like  Station Name,Station Code A N DEV NAGAR,ACND ABHAIPUR,AHA ABOHAR,ABS ABU ROAD,ABR ...   What I was trying was - trying to write a shell script and then echo them with comma in between. But I guess a simpler effective one-liner would do the job here may be in sed/awk.  Any ideas? Windows Batch recursive delete old files Is hyperref really the best way to add metadata to a TeX file? So I know one of hyperref's features is that it can add metadata to you PDFs. This is a nice feature and if you're putting stuff online, it's good to include metadata.  But is the hyperref package really the best way to do it? I mean, if you're using hyperref anyway, that's fine. But if you don't want hyperrefs in your document, it seems weird to include the package, and then turn off pretty much all its functionality. And given that hyperref is a shorthand for "package conflict nightmare", is seems insane that you should have to deal with it just for the sake of some metadata.  So I have two questions.   Is there a good reason that hyperref includes this functionality which is apparently unrelated to its primary purpose? Is there a better (smaller, less conflicty, easier...) option to include metadata in my PDFs? How should a family with young children apply for UK visas? How do I find duplicate values in a table in Oracle? Motivation for Ramanujan's mysterious $\pi$ formula The following formula for $\pi$ was discovered by Ramanujan: $$\frac1{\pi} = \frac{2\sqrt{2}}{9801} \sum_{k=0}^\infty \frac{(4k)!(1103+26390k)}{(k!)^4 396^{4k}}\!$$   Does anyone know how it works, or what the motivation for it is? Undefined Symbol ___gxx_personality_v0 on link Mis-aligned shapefiles in QGIS? Note: I will expand this question with more specific points when I have my own internet connection and more time (we're moving in, so I'm at a friend's house).  This question is broad, involved, and to some degree subjective.  (I started out as a physics-only student, but eventually decided to add a mathematics major. I am greatly interested in mathematics; the typical curriculum required for physics students is not deep or thorough enough; mathematics is more general (that means work!); and it only requires a few more classes. Naturally, I enjoy  immensely.)  This question asks mainly of undergraduate-level study, but feel free to discuss graduate-level study if you like.  Please do not rush your answer or try to be comprehensive. I realize the StackOverflow model rewards quick answers, but I would rather wait for a thoughtful, thorough (on a point) answer than get a fast, cluttered one. (As you probably know,  produces clear, useful writing; and a properly-done comprehensive answer would take more than a reasonable amount of time and effort.) If you think an overview is necessary, that is fine.  For a question this large, I think the best thing to do is focus on a specific area in each answer.    Update: To Sklivvz, Cedric, Noldorin and everyone else: I had to run off before I could finish, but I wanted to say I knew I would regret this; I was cranky and not thinking clearly, mainly from not eating enough during the day. I am sorry for my sharp responses and for not waiting for my reaction to pass. I apologize.  Re: Curricula:   Please note that I am not asking about choosing your own curriculum in college or university. I did not explicitly say that, but several people believed that was my meaning. I will ask more specific questions later, but the main idea is how a physics student should study mathematics (on his or her own, but also by choosing courses if available) to be a competent mathematician with a view to studying physics.  I merely mentioned adding a mathematics major to illustrate my conclusion that physics student need a deeper mathematical grounding than they typically receive.   And now I have to run off again. fetching list of friends using facebook 2.0