I was working on a problem from a MOOC, and had to give up and look at the solution. But I am not sure about a particular part of this solution. Here is the code:  def playGame(wordList): """ Allow the user to play an arbitrary number of hands.  1) Asks the user to input 'n' or 'r' or 'e'.   * If the user inputs 'n', let the user play a new (random) hand.   * If the user inputs 'r', let the user play the last hand again.   * If the user inputs 'e', exit the game.   * If the user inputs anything else, tell them their input was invalid.  2) When done playing the hand, repeat from step 1     """  turn = 0 user_input = ""  while user_input != 'e':     user_input = raw_input("Enter n to deal a new hand, r to replay the last hand, or e to end game: ")      if user_input == 'r' and turn ==0:         print "You have not played a hand yet. Please play a new hand first! \n"      elif user_input == 'r' and turn &gt; 0:         playHand(hand, wordList, HAND_SIZE)      elif user_input == 'n':         hand = dealHand(HAND_SIZE)         playHand(hand, wordList, HAND_SIZE)         turn = 1      elif user_input !='e':         print "Invalid command."   How is it possible that the value of hand doesn't reset to a new value? So for example, user input is "n" the first time around, and second time around the input is 'r'. Shouldn't there be no value for the hand variable? But in reality the value for hand is staying the same. Doesn't everything in the while loop reset when coming back around? Or am I wrong?
What exactly are the Python scoping rules?  If I have some code:  code1 class Foo:    code2    def spam.....       code3       for code4..:        code5        x()   Where is x found?  Some possible choices include the list below:   In the enclosing source file In the class namespace In the function definition In the for loop index variable Inside the for loop   Also there is the context during execution, when the function spam is passed somewhere else. And maybe  pass a bit differently?  There must be a simple reference or algorithm somewhere.  It's a confusing world for intermediate Python programmers.
I bought my kids a PC and installed 12.04 (Unity) on it.  The bottom line is, I want my children to use the computer unsupervised while I have confidence they cannot access anything inappropriate.  What I have looked at:  I was looking at Scrubit a tool which allows me configure my wifi router to block content and this solution would also protect my other PC and mobile devices.  This may be overkill as I just want the solution to work on one PC.    I also did some Google searches and came across the application called .  My experience of OSS is that the best solutions frequently never appear first on a Google search list and in this case I need to trust the methods therefore my question is very specific.   I want to leverage your knowledge and experience to understand What is the best way to restrict adult content on 12.04 LTS as this is important to me.  It maybe a combination of things so please don't answer this question "try this or that", then give me some PPA unless you can share your experience of how good it is and of course if there are any constraints. regexp in ksh for extensions tgz, tar.tgz I'm trying to get a regexp (in ksh) to identify files with only the following extensions: tgz, tar.gz, TGZ and TAR.GZ. I tried several but can't get them to work. I'm using this regexp to select only files files with those extensions to do some work with them:  if [ -f $myregexp ]; then    .....  fi How do I prove that $S^n$ is homeomorphic to $S^m \Rightarrow m=n$? This is what I have so far:  Assume $S^n$ is homeomorphic to $S^m$. Also, assume $m≠n$. So, let $m&gt;n$.  From here I am not sure what is implied. Of course in this problem $S^k$ is defined as:  $S^k=\lbrace (x_0,x_1,⋯,x_{k+1}):x_0^2+x_1^2+⋯+x_{k+1}^2=1 \rbrace$ with subspace topology. Does Stack Exchange use caching and if so, how? Recently, I read this  about how they have some of their infrastructure laid out. I was curious to know, does Stack Exchange use caching (both at the application layer and/or database layer) and if so, how? ST_Length (GEOM, true) for calculating distances in Geographic Reference System Can a Windows virus transfer to Ubuntu? One or more of the following things happened to me on a Stack Exchange site:   My post(s) were wrongly deleted or locked by a moderator A moderator posted a wrong comment on one of my posts I was suspended, but did not do anything wrong I asked a meta question, but the question was closed and/or deleted A moderator discredited me in public ...   I think a moderator has abused their power, but I feel powerless against them.  What recourse do I have now? What can I do when I feel that a moderator has abused their power, and has been repeatedly unfair in their dealings with me? How to fix "sudo: unable to open ... Read-only file system"? The title might not be as descriptive as I would like it to be but couldn't come up with a better one.  My server's file system went into Read-only. And I don't understand why it does so and how to solve it.  I can SSH into the server and when trying to start apache2 for example I get the following :  username@srv1:~$ sudo service apache2 start [sudo] password for username: sudo: unable to open /var/lib/sudo/username/1: Read-only file system  * Starting web server apache2                                                                                                                                                                                                               (30)Read-only file system: apache2: could not open error log file /var/log/apache2/error.log. Unable to open logs Action 'start' failed. The Apache error log may have more information.   When I try restarting the server I get :  username@srv1:~$ sudo shutdown -r now [sudo] password for username: sudo: unable to open /var/lib/sudo/username/1: Read-only file system   Once I restart it manually it just start up without any warning or message saying something is wrong.  I hope somebody could point me into the right direction to resolve this issue. As I understand it, anything created with an alloc, new, or copy needs to be manually released. For example:  int main(void) {     NSString *string;     string = [[NSString alloc] init];     /* use the string */     [string release]; }   My question, though, is wouldn't this be just as valid?:  int main(void) {     NSAutoreleasePool *pool;     pool = [[NSAutoreleasePool alloc] init];     NSString *string;     string = [[[NSString alloc] init] autorelease];     /* use the string */     [pool drain]; } Minimal sufficient statistic of $\operatorname{Uniform}(-\theta,\theta)$ Square of a second derivative is the fourth derivative I have a simple question for you guys, if I have this:  $$\left(\frac{d^2}{{dx}^2}\right)^2$$  Is it equal to this:  $$\frac{d^4}{{dx}^4}$$  Such that if I have an arbitrary function $f(x)$ I can get:  $$\left(\frac{d^2 f(x)}{{dx}^2}\right)^2 = \frac{d^4 f(x)}{{dx}^4}$$  Sorry if it's a pretty simple question, but I was trying to simplify something like this:  $$\left(a \cdot \frac{d^2}{{dx}^2} - f(x)\right)^2 g(x)$$ that's where it came up. Trying to overwrite ... which is different from other instances of package I tried to upgrade Intel graphics in ubuntu 16.10 using the official installer. The last stage of unpacking libcairo2 produces an error (see figure).  When I do upgrade I get the same error also:   Preparing to unpack .../0-libcairo2_1.15.2-0intel1_amd64.deb ... Unpacking libcairo2:amd64 (1.15.2-0intel1) over (1.15.2-0intel1) ... dpkg: error processing archive /tmp/apt-dpkg-install-aYhdFd/0 libcairo2_1.15.2-0intel1_amd64.deb (--unpack): trying to overwrite shared '/usr/share/doc/libcairo2/changelog.Debian.gz', which is different from other instances of package libcairo2:amd64 Preparing to unpack .../1-libcairo2_1.15.2-0intel1_i386.deb ... Unpacking libcairo2:i386 (1.15.2-0intel1) over (1.15.2-0intel1) ... dpkg: error processing archive /tmp/apt-dpkg-install-aYhdFd/1-libcairo2_1.15.2-0intel1_i386.deb (--unpack): trying to overwrite shared '/usr/share/doc/libcairo2/changelog.Debian.gz', which is different from other instances of package libcairo2:i386 Errors were encountered while processing: /tmp/apt-dpkg-install-aYhdFd/0-libcairo2_1.15.2-0intel1_amd64.deb /tmp/apt-dpkg-install-aYhdFd/1-libcairo2_1.15.2-0intel1_i386.deb E: Sub-process /usr/bin/dpkg returned an error code (1)   It seems that there is a conflict in thelibcairo releases; if yes, how to resolve it ? How do I save/remember last-used window position and size for applications? Big tilde in math mode How to change language of a specific application? What is "superuser" and how do I get that privilege? With the last update of Fallout Shelter, Bethesda has added these "limited time" quests.  Question is, how limited is that time exactly? What happens when the quests "end", will it still be possible to get the benefits? Reference for creative set criterion theorem Can I accept an already rejected edit (to my own post)? Today,  to one of . Before I got to see the notification, the edit already was rejected by other people (three rejections, one approval).  But the edit was actually a good one (like most edit proposals to my post I get to see) – a correction of syntax errors, so I would have definitively approved it.  (The suggested edit didn't change the main point of the answer, which was about the API to use, but it made the code example of my answer actually usable. I didn't compile it when writing my answer, it was late at the evening.)  So I did edit my post to include the proposed change, so the proposal is not fully lost. But the proposer only got the negative feedback from the rejection, and none of the reputation bonus an accepted edit gives.  My suggestion: Could there be added a way a post author can accept edits which were already rejected by other users?  Also, is there some way I can contact the rejectors and teach them not to reject good edits? I am using setInterval(fname, 10000); to call a function every 10 seconds in JavaScript. Is it possible to stop calling it on some event?   I want the user to be able to stop the repeated refresh of data.