Here, the content of parenthesis means superclass.   class Tag(enum.Enum):     a = 1     b = 2 if __name__ == '__main__":     print(Tag.a)   output is as follows:  Tag.a   After I replaced "Tag.a" with "Tag.a.value", I got the output as follows:  1   Why is class variable' s type the superclass's type? I can't understand the code. Please interpret the result as explicitly as possible.
I'm mainly a C# developer, but I'm currently working on a project in Python.  How can I represent the equivalent of an Enum in Python?
I need help identyfying this movie I once saw late night on TNT, late 90s or early 2000s.  I don't have very clear recollection about it. The movie was very strange. It all took place in a single room of a spaceship or an escape pod that had lost power. A woman and a man, or several men, were stuck in a ship or a spacepod that was somehow damaged or didn't have power.   The movie was entirely made of the dialogs between the woman and the man (or men). They would talk about what was happening outside, how to contact help, about their lives. During their conversation details about the world around them emerge. In this movie people have colonized the solar system but not moved outside it, and there is some sort of a war.  Other things I remember are that it was dark in that room. I think they used only a lightbulb or even direct starlight and sunlight (if they were far away from the sun), because there was no power. Also it was getting colder, becaus the ship's heating system was not functioning, and so it was losing its heat. The people would constantly complain about how cold it's getting. I think that the woman was the captain of the ship. She would sometimes go to the control cabin and try to do something to help their situation, either restore power or contact someone so they can be rescued.  What impressed me about it was how they managed to make it realistic. Because the actors would talk and act like it was all real, it made it somehow feel very realistic to me as well.  That's about it as far as I remember. Hope someone has watched this movie and can tell me what it is.  Update  I want to add a few more details about the movie. While I watched it in the late 90s/early 2000s the movie looked much older. It looked like a vintage B-Movie made in the style of the 70s or 80s. In particular the decor looked more like Alien 1 or Cosmos 1999.   I just watched the firefly episode and it can't be it. It has too much action, and the atmosphere is not dark enough. Integrating MySQL with Python in Windows How can I edit/create new launcher items in Unity by hand? Will Unity allow making custom launcher icons from .desktop files or via menu editing system? (Right now the launcher doesn't give the option to "keep in launcher" on all programs.  For some programs I use, I have to make custom launchers or .desktop files.  For instance, daily blender builds are generally just folders with an executable.  In basic Gnome or KDE, I can make a new menu entry with the menu editing system. Then, I can also add it to Docky either from the menu or by dragging a .desktop file to it. Unity launcher doesn't support drag and drop, so thats not a bug or anything, but when I open a .desktop file, it has unpredictable results. Most time it will not have "keep in launcher". Sometime it will have a pinnable item without the .desktop's icon, and if I pin the item to the launcher, it will not call upon the program again after closing it. I've also gotten it to just work with a .desktop file for celtx. Find joint density function of X and X+Y (exponential distribution) I tried finding the following density function:     Let $X$ and $Y$ be independent random variables, each having the exponential distribution with parameter $\lambda$. Find the joint density function of $X$ and $Z=X+Y$.   $\begin{aligned}f_{X,X+Y}=&amp;\frac{\partial}{\partial x\partial z}\mathbb P (X\leq x,Y\leq z-x)\\=&amp;\int_{-\infty}^x\int_{-\infty}^{z-x}f(u,v)\,\mathrm dv=\frac{\partial}{\partial z}\left[\frac{\partial}{\partial x}\int_0^x\int_0^{z-x}\lambda^2e^{-\lambda u-\lambda v}\,\mathrm dv\,\mathrm d u\right]\\ =&amp;\frac{\partial}{\partial z}\int_0^{z-x}\lambda^2e^{-\lambda x-\lambda v}\,\mathrm dv=\frac{\partial}{\partial z}\int_x^{z}\lambda^2e^{-\lambda x-\lambda(v-x)}\,\mathrm dv\\ =&amp;\lambda^2e^{-\lambda x-\lambda(z-x)}=\lambda^2e^{-\lambda z} \end{aligned}$  But I don't think this is correct, because $\mathbb P(X\leq x,X+Y\leq z)$ isn't equal to $\mathbb P(X\leq x,Y\leq z-x)$. But I can't think of anything else.  Could someone help me a little bit with this exercise?  I'm going to try the following:  $\mathbb P(X\leq x,Z\leq z)=\int_{-\infty}^x\int_{-\infty}^zf_X(u)f_Z(v)\,\mathrm du\,\mathrm dv$,  where I use the convolution formula. If I made no mistake, this gives  $f_{X+Y}(z)=z\lambda^2e^{-\lambda z}$, if $z&gt;0$.  Then calculating the joint density function:  $\begin{aligned}f_{X,X+Y}(x,z)=\frac{\partial}{\partial z}\left[\int_{-\infty}^z\lambda^3ve^{-\lambda x-\lambda v}\,\mathrm dv\right]. \end{aligned}$  Oh wait, this is also incorrect, because $X$ and $X+Y$ are dependent.  I really don't know how to proceed; could someone help?  I've also looked at this , but they mention the Jacobian, and my teacher has chosen to skip the paragraph about the Jacobian, so it wouldn't make sense if I had to use that. Can you change your email for Pokemon Go? Why do I get "unresolved external symbol" errors when using templates? When I write C++ code for a class using templates and split the code between a source (CPP) file and a header (H) file, I get a whole lot of "unresolved external symbol" errors when it comes to linking the final executible, despite the object file being correctly built and included in the linking.  What's happening here, and how can I fix it? How do I change my login provider(s)? I no longer use the service that I originally used to register, and would like to change the service I use to log in, or at least add a second account.  Is this possible? How do I change my login provider or associate a backup method to log in?     For more information, see "" in the . What should a main game loop do? Generally, what are the core things that one should do in the game loop, and what are some things that one shouldn't do in the game loop? Compatible version of "Adobe Shockwave Player?" Is there a Ubuntu compatible version of the "Adobe Shockwave Player?" I'm running Firefox and when I try to bring up one of my School's websites it says missing plugin. When I click on "Install missing plug-in" it says none found, so when I click on manually install plug-in it takes me to Adobe Shockwave Player installation, but there is no ubuntu version to install??? On the Firefox plug-in finder service it says "Unknown Plugin (application/x-director) The game  has a very unique intro that I would like to show my friend again for the first time. I'm not sure how to reset all my progress on this game to achieve this though. Any thoughts? Goal: I have a function $f(x,y)=z$ (two variables for illustration only) which I know almost nothing about--it has a compact domain which I can determine, it is non-negative, and bounded above.  My goal is to find the maximum value $f(x,y)$ takes on its domain.  I can query the function and I know the values at a few points: $f(x_1, y_1)=z_1, f(x_2, y_2)=z_2,..., f(x_n, y_n)=z_n$.  Optimization via Linear Regression:  I have used linear regression (and related methods like the lasso) to model functions like this in the past; this is the method that I am very comfortable with.  Typically, I might try to find a polynomial (of degree $k$) which relatively accurately models the data. The end result would be to say that:   $$f(x,y)\approx \beta_1 + \beta_2 x + \beta_3 y + \beta_4 x^2 + \beta_5 xy + \beta_6 y^2 + ... + \beta_{m}y^{k}.$$  Determining the coefficients is done by solving the .  The "best degree" for the polynomial might be determined using $k$-fold cross validation.  Once the "best" polynomial has been determined, one can choose any of a number of methods to optimize it (Newton's method, gradient descent, hill climbing, etc).  Then, if all goes well, the optimal value on the polynomial corresponds to an optimal value of $f(x,y)$.  Bayesian Optimization:  Recently, I was describing this technique (linear regression) to a colleague who asked: "What is the difference between that and Bayesian Optimization?"  I've been attempting to answer this question for the last couple days, and so far I don't have anything really conclusive.  After reading , trying to read  and getting stuck reading  I think I understand the following about BO:   Start with a prior (a guess as to what family of functions the black box belongs to... or at least some family of functions which you believe might be able to describe $f$ well).  It looks using a  as a prior is popular. Specify whatever is needed to build your prior (for GP this is a covariance function). As you go along, you maintain two evolving functions, a "mean" function $m(x,y)$ and a "confidence interval" function $c(x,y)$.  Basically, you can predict the value at any point by evaluating $m(x,y)$ and you are confident that $f(x,y)\in [m(x,y)-c(x,y), m(x,y)+c(x,y)]$. Bayesian optimization provides a systematic way of updating/exploiting the model by alternatively selecting points where the confidence interval is wide (you are very uncertain about the value) or at optimal points on the model $m(x,y)$.   My Question: Is it fair/correct to say that the major difference between Bayesian Optimization and simply optimizing the linear regression model is that Bayesian Optimization provides the systematic way of sampling with the goal of optimizing the model and reducing uncertainty whereas the linear regression model ignores the idea of uncertainty and doesn't explicitly provide a means of updating the model?  Said another way, is the linear regression model an example of what might be a "mean" function $m(x,y)$ in Bayesian Optimization?  If I stick with linear regression, specify how to compute the uncertainty, and provide a means of updating/improving the model (exploit/explore) am I just doing Bayesian Optimization (without calling it that)?  Background: My background is in pure mathematics (graph theory) but my new job has me working with a lot of data (so I'm self learning statistics).  With that in mind, my statistics vocabulary is somewhat limited (so I appreciate answers that either avoid technical terminology or briefly explain any technical terminology used)--for example, Monday was the first time I heard/read the word "prior" used in a stats sense and I'm still not 100% sure I understand that correctly. The merits of a partitionless filesystem I ran into something a couple of weeks ago that I'd never seen before: A filesystem (ext3 I believe) installed to a storage device without a partition. In essence /dev/sdb was the entire filesystem. I know many filesystems can be extended into empty space, so doing this allows extending without dealing with LVM or some other kind of volume manager, but are there any other advantages for setting up storage this way?  The specific case I saw was as the ephemeral data volume for a number crunching server, the boot and root volumes were traditional partitions on a different storage device entirely. - How to parse a string into a nullable int I'm wanting to parse a string into a nullable int in C#.  ie. I want to get back either the int value of the string or null if it can't be parsed.  I was kind of hoping that this would work  int? val = stringVal as int?;   But that won't work, so the way I'm doing it now is I've written this extension method  public static int? ParseNullableInt(this string value) {     if (value == null || value.Trim() == string.Empty)     {         return null;     }     else     {         try         {             return int.Parse(value);         }         catch         {             return null;         }     } }      Is there a better way of doing this?  EDIT:  Thanks for the TryParse suggestions, I did know about that, but it worked out about the same.  I'm more interested in knowing if there is a built-in framework method that will parse directly into a nullable int? I am trying to retrieve list items using date range based on date column. It implicit both 'Fromdate' and 'Todate'.My CAML query is also querying on two other conditions as well. I am using the below query but it is not retrieving the data.when I remove the date range from query data is retrieved fine. But i want date range as well in my query how would i do this. Little help would work for me.   camlQuery.set_viewXml('&lt;View&gt;&lt;Query&gt;&lt;Where&gt;&lt;And&gt;&lt;And&gt;&lt;Neq&gt;&lt;FieldRef Name="ID" /&gt;&lt;Value Type="Number"&gt;0&lt;/Value&gt;&lt;/Neq&gt;&lt;Eq&gt;&lt;FieldRef Name="_ModerationStatus" /&gt;&lt;Value Type="ModStat"&gt;0&lt;/Value&gt;&lt;/Eq&gt;&lt;Geq&gt;&lt;FieldRef Name="Created" /&gt;&lt;Value Type="DateTime"&gt;' + fromDate + '&lt;/Value&gt;&lt;/Geq&gt;&lt;Leq&gt;&lt;FieldRef Name="Created" /&gt;&lt;Value Type="DateTime"&gt;' + toDate + '&lt;/Value&gt;&lt;/Leq&gt;&lt;/And&gt;&lt;/And&gt;&lt;/Where&gt;&lt;OrderBy&gt;&lt;FieldRef Name="_ModerationStatus" Ascending="True" /&gt;&lt;/OrderBy&gt;&lt;/Query&gt;&lt;/View&gt;'); When I get a notification on android that someone had posted an answer or comment, if I click the notification, it opens the Stack Exchange app but shows the main view with the inbox opened, not the comment or answer that was in the notification.  If there is only one notification pending, when you tap it it should show you the actual contents rather than just the inbox. What does echelon mean? When you solve a system of linear equations, you write down the augmented matrix and reduce this to reduced row echelon form. What is the meaning of the word echelon? Multi-Question Questions: How Best to Handle Them? Sometimes I come across a question on SO that is actually a number of questions all in one. If these &quot;sub-questions&quot; are closely related, it's not a problem. But if they are only weakly related (or not at all) it gets ugly. I'm now (ironically or hypocritically) going to ask a few questions of my own for the community to respond to:  Do you consider a question made up of a number of weakly-related sub-questions &quot;inappropriate&quot;? Why or why not? How many is too many sub-questions? What do you think is the best way to deal with such questions?  As an example,  I had some discussion about with another user. I will add a more complete version of my response in an answer below, but in short I felt that this question should be closed and many of the questions asked separately. Remove paint from the head tube I'm planning to build a new bike from scratch.  Part of that is buying a new frame, and possibly facing/reaming it. That's actually the part I'm scared of the most.  Fortunately, the brand I'm targeting, Surly, seems to do that in the factory. But as they state, there may be some paint left where it should not be:     Since Surly frames are faced prior to painting, it is possible to   shave the paint off the head tube and BB shell ends with a carpet   knife blade.  This usually results in an acceptable result, saving you   money, but we still recommend having it done the proper way to ensure   longest life from your components.   So what is the "proper way" to remove the extra paint, if the frame is properly reamed/faced already?  Should I choose not to do it the proper way, which components are going to suffer? I suppose at least the headset and bottom bracket, but could the frame suffer as well? Linked and Related sections contain duplicate links to questions The Linked and Related sections sometimes contain a link to same same question.  See for example , where one of the Linked questions is same as the first of the Related questions.  I think that this is redundant and duplicate links should be removed from Related section. What is the name of the default font in math mode? I draw figures in Inkscape. When I label elements within the figures with variable names that I have used in the underlying TeX document, I would like them to look exactly the same as in the document. (e.g. l does not look the same as $l$)  What is the name of the math mode font so I can select it correctly in the Inkscape font list?  If the exact font should not be available, what is a similar looking font that is present on most systems?