I have a list of lists of values. In some instances, I have to print names of the lists but not their values.   onesoil = [dates_bwn_twodates('2019-03-22','2019-04-09'),onemod] sixsoil = [dates_bwn_twodates('4/10/2019','4/29/2019'),sixmod] explist = [onesoil,sixsoil]   print(explist[0])  &gt;&gt;  [dates_bwn_twodates('2019-03-22','2019-04-09'),onemod]   Above is fine but I want to print the name but not is value.   My expected output   print(explist[0]) &gt;&gt; onesoil    How to achieve this?
I have enum and use the variables like myEnum.SomeNameA, myEnum.SomeNameB, etc.  When I return one of these variables from a function, can I print their names (such as myEnum.SomeNameA) instead of the value they returned?
How can I make ffmpeg be quieter/less verbose? By default ffmpeg sends a whole lot of messages to stderr: when built, how it was built, codecs, etc, etc, etc.  How can I make it quieter?  I've tried -v 0 (and -v 10 since the documentation just coyly says Set the logging verbosity level. with no indication of what the range of inputs is) -- still not quiet.  I've tried -loglevel quiet -- still not quiet.  I should mention, I'm looking for "quieter," not "no output ever".  If there's an error I want to see it, but I don't need to hear about ffmpeg's configuration every. single. time. The definition for marker below is from tcolorbox.doc.s_main.sty. With earlier versions of Texlive (and tcolorbox), this worked fine, but with updated Texlive, it does not.  \documentclass{article} \usepackage{xcolor,tikz,tcolorbox} \usetikzlibrary{shadows} \tcbuselibrary{skins,hooks} \makeatletter % from tcolorbox.doc.s_main.sty \newtcolorbox{marker}[1][]{enhanced,   before skip=2mm,after skip=3mm,   boxrule=0.4pt,left=5mm,right=2mm,top=1mm,bottom=1mm,   colback=yellow!50,   colframe=yellow!20!black,   sharp corners,rounded corners=southeast,arc is angular,arc=3mm,   underlay={%     \path[fill=tcbcol@back!80!black] ([yshift=3mm]interior.south east)--++(-0.4,-0.1)--++(0.1,-0.2);     \path[draw=tcbcol@frame,shorten &lt;=-0.05mm,shorten &gt;=-0.05mm] ([yshift=3mm]interior.south east)--++(-0.4,-0.1)--++(0.1,-0.2);     \path[fill=yellow!50!black,draw=none] (interior.south west) rectangle node[white]{\Huge\bfseries !} ([xshift=4mm]interior.north west);     },   drop fuzzy shadow,#1} \makeatother   \begin{document} \begin{marker}   Hylo! \end{marker}  \end{document}   This gives the following error  ! Package xcolor Error: Undefined color `tcbcol@back'.  See the xcolor package documentation for explanation. Type  H &lt;return&gt;  for immediate help.  ...                                                l.34 \end{marker}  ?   Why are tcbcol@back and tcbcol@frame undefined if they work in the code for the package's documentation? Alternatively, what are the correct names for the colours which were tcbcol@back and tcbcol@frame?  My version of tcolorbox is 2019-09-19. Who is doing the normalization of wave function in the time evolution of wave function? In the Schrödinger equation, at any given time $t$ we should jointly add another sub equation, like $$||\psi_t(x)|| = 1$$ where $\psi_t(x) = \Psi(x,t)$, and then try to solve the two equations simultaneously. Why not? I know it does not yield, but I am always baffled, who is doing the normalization of the wave function? Observers, the system, the measuring process, God? (I was requested to edit the question to explain why it is different that a proposed duplicate question. This seems counterproductive to do here, inside the question it self, but that is what I have been asked by the site and moderators. There is no way for me to vote against their votes. So, here I go: Please stop voting this as a duplicate so quickly, which will eventually lead to this question being closed off. Yes, the other question linked to asks the same math, but any newcomer to the problem who was exposed to it via physics, as I was, will prefer this question instead of the one that is purely mathematically. I beg the moderators to not be pedantic on this one. This question spills into physics, which is why I did the cross post to the physics forum as well.)  How does the sum of the series “1 + 2 + 3 + 4 + 5 + 6…” to infinity = “-1/12”, in the context of physics?  I heard Lawrence Krauss say this once during a debate with Hamza Tzortzis (). I found a transcript of another debate between Krauss and William Lane Craig which has the same sum. Here is the paragraph in full:     Let’s go to some of the things Dr. Craig talked about. In fact, the   existence of infinity, which he talked about which is   self-contradictory, is not self-contradictory at all. Mathematicians   know precisely how to deal with infinity; so do physicists. We rely on   infinities. In fact, there’s a field of mathematics called “Complex   Variables” which is the basis of much of modern physics, from   electro-magnetism to quantum mechanics and beyond, where in fact we   learn to deal with infinity; without the infinities we couldn’t do the   physics. We know how to sum infinite series because we can do complex   analysis. Mathematicians have taught us how. It’s strange and very   unappetizing, and in fact you can sum things that look ridiculous. For   example, if you sum the series, “1 + 2 + 3 + 4 + 5 + 6…” to infinity,   what’s the answer? “-1/12.” You don’t like it? Too bad! The   mathematics is consistent if we assign that. The world is the way it   is whether we like it or not.   -- Lawrence Krauss, debating William Lane Craig, March 30, 2011  Source:   CROSS POST: I'm not sure if I should post this in mathematics or physics, so I posted it in both. Cross post:   EDIT: I did not mean to begin a debate on why Krauss said this. I only wished to understand this interesting math. He was likely trying to showcase Craig's lack of understanding of mathematics or logic or physics or something. Whatever his purpose can be determined from the context of the full script that I linked to above. Anyone who is interested, please do. Please do not judge him out of context. Since I have watched one of these debates, I understand the context and do not hold the lack of a full breakdown as being ignorant. Keep in mind the debate I heard this in was different from the debate above. Find the minimal polynomial for $\sqrt[3]{2} + \sqrt[3]{4}$ over $\mathbb{Q}$  I havent covered galois theory, this is an exercise from the chapter algebraic extensions in gallian.  I can see that $\sqrt[3]{2} + \sqrt[3]{4}$ $\in \mathbb{Q}(2^{1/3})$, after this I am clueless.  Need hints will finish the proof. When should "Mom" and "Dad" be capitalized? I am trying to understand capitalization rules with Mom and Dad. I believe I have it correct below, but please let me know if I do not.     The one thing I learned from my dad was that it was good to earn the trust of one's children. Dad has shown me how good that a dad can be. One day when I went to his house, and Dad wasn't there, I ran outside....   The above passage is just made-up just so that you would see what I mean about capitalization. Let's put numbers by each one, like so:     The one thing I learned from my dad(1) was that it was good to earn the trust of one's children. Dad(2) has shown me how good that a dad(3) can be. One day when I went to his house, and Dad(4) wasn't there, I ran outside....    This is one where I'm not certain. I believe in this sense I'm showing possession here with "my", and it just didn't seem right saying "my Dad". I don't know what the grammar rule is here, or if I even have it right. This one is obvious—it starts the sentence. In this case, I'm using Dad like a name instead of saying "Larry". Therefore, it should be capitalized. Again, just like 3. Jewish Law prohibits the  However, butter, a milk product, is a kitchen staple for most cooked emulsions (eg. pan-sauces, sauces béchamels, or roux-based sauces). While I use appropriate cooking fats for making non-dairy versions for meat dishes, this frequently doesn't work.  What is a non-dairy fat which may be used to as an emulsifier or roux ingredient? Intuition behind logarithm change of base I try to understand the actual intuition behind the logarithm properties and came across  that explains the multiplication and thereby also the division properties very nicely:     Suppose you have a table of powers of 2, which looks like this: (after revision)      $$\begin{array}{rrrrrrrrrr} 0&amp;1&amp;2&amp;3&amp;4&amp;5&amp;6&amp;7&amp;8&amp;9&amp;10\\ 1&amp;2&amp;4&amp;8&amp;16&amp;32&amp;64&amp;128&amp;256&amp;512&amp;1024 \end{array}$$      Each column says how many twos you have to multiply to get the number in that column.  For example, if you multiply 5 twos, you get $2\cdot2\cdot2\cdot2\cdot2=32$, which is the number in column 5.      Now suppose you want to multiply two numbers from the bottom row, say $16\cdot 64$.  Well, the $16$ is the product of 4 twos, and the $64$ is the product of 6 twos, so when you multiply them together you get a product of 10 twos, which is $1024$.   I found that very helpful to understand the actual proofs for this property.  I still struggle to get the idea behind the change of base rule. I'm familiar with the proof that goes like:  $$\log_a x = y \implies a^y = x$$ $$\log_b a^y = \log_b x$$ $$y \cdot \log_b a = \log_b x$$ $$y = \frac{\log_b x}{\log_b a}$$  But can somehow provide a explanation in the style of the quoted answer why this actually works? PGFplots foreach equivalent to TikZ's with multiple variables separated by a slash In Season 6, we find out the following about the magical properties of the wall:     BENJEN: This is where I leave you.   BRAN: You're not coming with us?   BENJEN: The Wall is not just ice and stone. Ancient spells were carved into its foundations. Strong magic to protect men from what lies beyond. And while it stands, the dead cannot pass. I cannot pass.   —"Winds of Winter" (Game of Thrones, S06E10)   So why would the men of Westeros need to worry about the Night King and his army? Couldn't they sit back and enjoy the wall's protection? Link2SD not working completely My Link2SD doesn't seem to be fully working. I noticed this when updating the Facebook application. Google Play prompted me of insufficient storage. I first uninstalled some apps but I got curious so I checked Link2SD's storage info, I got this:   (Click image to enlarge)  As you can see, the internal storage only has mere 70mb left. What's peculiar is, these are the only apps I have NOT linked:   (Click image to enlarge)  I tried moving one linked app (Amazing Alex) to the sd card (normal Android way) and sure enough, the free space on my internal storage got bigger by about an additional 20mb-ish.  Why is this happening? Why isn't Link2SD moving the data to my sdext2? How do I solve it? What is a word for someone without allegiance? Which is the best way to put function plots into a LaTeX document? The square root of a prime number is irrational How to control a motor with only relays and push button? Hello I´ve been working in this project for some days, I need to make a circuit with only relays that can make a dc motor start, stop and a reverse. The thing is that when you push the start or the reverse button the motor need to keep running, I can´t keep it pushed.  This is as far as I can get. SW1 turns the engine on, SW5 turns it off and SW7 reverse the motor but only if it is already running. What i need is that the reverse button also turns the engine on. Please help.  notes: -i can only use three push buttons and as many relays as needed. Yes is a school assignment.  THANKS! Who is the Community user? Kill the [bugs] tag? It seems most of the questions tagged  on Stack Overflow are just intended to indicate "there's something wrong with my program", which would cover probably at least 80% of all questions on Stack Overflow.  There are some questions where it seems to refer to a possible bug in a framework or utility. I'm not sure the tag is really all that useful in that case either.  What does meta think? Initializing K-means centers by the means of random subsamples of the dataset? If I have a certain dataset, how smart would it be to initialize cluster centers using means of random samples of that dataset?  For example, suppose I want 5 clusters. I take 5 random samples of say, size=20% of the original dataset. Could I then take the mean of each of these 5 random samples and use those means as my 5 initial cluster centers? I don't know where I read this but I wanted to know what you guys think about the idea.    UPDATE: Please see this thread  for the general discussion about the various initialization methods. Is it possible to have two background images?  For instance, I'd like to have one image repeat across the top (repeat-x), and another repeat across the entire page (repeat), where the one across the entire page is behind the one which repeats across the top.  I've found that I can achieve the desired effect for two background images by setting the background of html and body:  html {     background: url(images/bg.png); }  body {     background: url(images/bgtop.png) repeat-x; }   Is this "good" CSS?  Is there a better method?  And what if I wanted three or more background images? Possible Duplicate:          I tried to color only a cell of my table but I don't know how do it. I found the method to color an entire row.How could I color only a cell of my table of a precise color?