I am unable to figure out the output of the following program  big_num_1   = 1000 big_num_2   = 1000 small_num_1 = 1 small_num_2 = 1 big_num_1 is big_num_2 # False small_num_1 is small_num_2 # True   What is happening above? Why is one False and other True.  Source:
Why does the following behave unexpectedly in Python?  &gt;&gt;&gt; a = 256 &gt;&gt;&gt; b = 256 &gt;&gt;&gt; a is b True           # This is an expected result &gt;&gt;&gt; a = 257 &gt;&gt;&gt; b = 257 &gt;&gt;&gt; a is b False          # What happened here? Why is this False? &gt;&gt;&gt; 257 is 257 True           # Yet the literal numbers compare properly   I am using Python 2.5.2. Trying some different versions of Python, it appears that Python 2.3.3 shows the above behaviour between 99 and 100.  Based on the above, I can hypothesize that Python is internally implemented such that "small" integers are stored in a different way than larger integers and the is operator can tell the difference. Why the leaky abstraction? What is a better way of comparing two arbitrary objects to see whether they are the same when I don't know in advance whether they are numbers or not?
How do I get the MAX row with a GROUP BY in LINQ query? In the inline math mode ($...$), if the formula is too long, LaTeX will try to break it on operators, e.g.  very long text followed by a very long equation like $a+b+c+d+e+f+g+h+i+j+k+l$ etc   may be rendered as  very long text followed by a very long equation like a+b+c+d+e+f+g+h+i+ j+k+l etc   However, the break won't happen if they are separated by commas, e.g.  very long text followed by a very long equation like $a,b,c,d,e,f,g,h,i,j,k,l$ etc   will overflow the page like  very long text followed by a very long equation like a,b,c,d,e,f,g,h,i,j,k,l etc   How to make LaTeX able to insert line breaks after a comma too? Deleting files from Remote FTP-Server older than x days i've got a remote FTP server where i store some backups via cronjob.  The Problem is that i only got a little amount of space so im doing incremental backups. I want to keep the backups about 14 days.  I don't have any other access to the server except FTP and i don't now how to delete files older than x days. Every file got a name with a date in it  yxzNamezxy-date-y-m-d.tar.bz2 (datev-20100111.tar.bz2(   Hope to get some help here.  Cheers and thanks for the hopefully coming answeres,  Dennis  /Edit  I'm trying to use the curl thing which is mantioned in an answere with this part of code  curl ftp://$FTP_SERVER --user $FTP_USER:$FTP_PASS --list-only &gt; files.tmp declare -a aFiles let iCount=0 exec &lt; files.tmp while read sLine do         aFiles[$iCount]=$sLine         ((iCount++)) done  echo -e "\n Files: \n\n\n" echo ${aFiles[@]}  echo -e "\nfor ...\n\n\n" for sFile in $aFiles do         echo -e "\nFile:" $sFile done   but the secound loop doesn't give me more than 1 filename  Cheers,  Dennis Question regarding an inequality How to prove that $$ \frac{x_1}{1+x_1^2}+\frac{x_2}{1+x_1^2+x_2^2}+\cdots+\frac{x_n}{1+x_1^2+\cdots+x_n^2}&lt;\sqrt{n} $$ knowing that $(x_n)$ is a positive sequence ? I looked up all kinds of inequalities such AM-GM, Chebyshev, Cauchy-Schwarz, but I couldn't manage to obtain anything useful.. Can anyone help ? Please add a system to allow file uploads attached to questions and answers Is there any way to generalise this problem? Is it acceptable to change the vid column of a term programmatically in the database? I need to move some terms from one vocabulary to another by retaining all their data: translations, aliases, and node references.  Is it acceptable to change its vid column value directly in the database? The terms don't have hierarchy relationships which needs to be handled. i want to create new event in SharePoint calendar list in which I have some custom columns,i tried below code but it is not working      function bookingRoomForMeeting() {         var ctx = new SP.ClientContext(appWebUrl);//Get the SharePoint Context object based upon the URL           var list = ctx.get_web().get_lists().getByTitle("MyCalendarList"); //Get the List based upon the Title         var listCreationInformation = new SP.ListItemCreationInformation(); //Object for creating Item in the List         listItem = list.addItem(listCreationInformation);         listItem.set_item('Title', $("#txt_Title").val());         var date = $("#txt_startTime").val();         var dateTime = moment(date, 'DD/MM/YYYY HH:mm a').format("MM/DD/YYYY HH:mm a");         listItem.set_item('EventDate', dateTime);         var enddate = $("#txt_endTime").val();         var enddateTime = moment(enddate, 'DD/MM/YYYY HH:mm a').format("MM/DD/YYYY HH:mm a");         listItem.set_item('EndDate', enddateTime);         listItem.set_item('EmailId1', $("#txt_EmailId1").val());         listItem.set_item('EmailId2', $("#txt_EmailId2").val());         listItem.update();         ctx.load(listItem);         ctx.executeQueryAsync(             Function.createDelegate(this, success),             Function.createDelegate(this, fail)            );     } function success() {     alert("Completed"); } function fail() {     alert("operation failed"); }   list am using is SharePoint hosted app list,can any one tell me where am going wrong? Setting background-image using jQuery CSS property Let $E|F$ be an algebraic field extension and a ring $K$ such that $F\subseteq K\subseteq E$. It is true that $K$ is a field? Is there any way to do n-level nested loops in Java? In other words, can I do something like  for() {     for {        for {        }     } }   Except N times? In other words, when the method creating the loops is called, it is given some parameter N, and the method would then create N of these loops nested one in another?  Of course, the idea is that there should be an "easy" or "the usual" way of doing it. I already have an idea for a very complicated one. Understanding backtick (`) Creating or adding geometry colunm fails even with postgis enabled Product of path connected spaces is path connected Auto mount a disk drive in ubuntu 14.04 LTS (Bookmark directory not found) I'm using ubuntu 14.04 LTS. When I start my pc and click on any bookmark from the file manager it shows this error:   Unable to find the requested file. Please check the spelling and try again. Unhandled error message: Error when getting information for file '/media/angel/DOC/edu': No such file or directory   But when I open DOC drive and again clink on the same bookmark it works properly. Can anybody tell me why is this happening and how to solve this issue?   Edit: Output of lsblk is following: (ubuntu is installed in sda5)  NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT sda      8:0    0 119.2G  0 disk  ├─sda1   8:1    0  91.3G  0 part  ├─sda2   8:2    0     1K  0 part  ├─sda5   8:5    0  24.1G  0 part / └─sda6   8:6    0   3.8G  0 part [SWAP] sdb      8:16   0 465.8G  0 disk  ├─sdb1   8:17   0  93.2G  0 part  ├─sdb2   8:18   0     1K  0 part  ├─sdb5   8:21   0  93.2G  0 part  ├─sdb6   8:22   0  89.3G  0 part  ├─sdb7   8:23   0  93.2G  0 part  ├─sdb8   8:24   0  93.2G  0 part  └─sdb9   8:25   0   3.8G  0 part  sr0     11:0    1  1024M  0 rom     After opening the disk drive the output of lsblk is bellow:   NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT sda      8:0    0 119.2G  0 disk  ├─sda1   8:1    0  91.3G  0 part  ├─sda2   8:2    0     1K  0 part  ├─sda5   8:5    0  24.1G  0 part / └─sda6   8:6    0   3.8G  0 part [SWAP] sdb      8:16   0 465.8G  0 disk  ├─sdb1   8:17   0  93.2G  0 part  ├─sdb2   8:18   0     1K  0 part  ├─sdb5   8:21   0  93.2G  0 part  ├─sdb6   8:22   0  89.3G  0 part /media/angel/DOC ├─sdb7   8:23   0  93.2G  0 part  ├─sdb8   8:24   0  93.2G  0 part  └─sdb9   8:25   0   3.8G  0 part  sr0     11:0    1  1024M  0 rom   The output of sudo blkid gives the following information about sdb6:  /dev/sdb6: LABEL="DOC" UUID="04280A22280A12FA" TYPE="ntfs" understanding the commutator of dihedral group Let  $G=D_{2n}=⟨x,y|x^2=y^n=e,  $ $yx=xy^{n-1}⟩$  I need to find $G'$ [ the commutator of G]  now I understand that $G'$ is the subgroup generated from $ U=xyx^{-1}y^{-1} , $ $ \ \forall x,y \in G$ So, $U=&lt;y^2&gt;$  whats the strategy  here ? In Mootools, I'd just run if ($('target')) { ... }.  Does if ($('#target')) { ... } in jQuery work the same way? Is my expansion of the state $| x \rangle$ correct? In my quantum mechanics textbook it says that the relation between the basis $|x\rangle$ and $|p\rangle$ is given by:  $\langle p | x \rangle = \Large \frac{e^{-ip x/ \hbar}}{\sqrt{2\pi \hbar}} \, .$  However, i'm not sure how to go about proving this relation. My idea was that the eigenstates of momentum can be written as below:  $\phi(x,p) = \Large \frac{1}{\sqrt{2\pi \hbar}} e^{-ipx/\hbar},$  which form an orthogonal basis.  But, we can expand any state, $|\text{state}\rangle$, in terms of the othorgonal basis right? So is my notation below correct for the expansion of the state $| x \rangle$ ?  $|x\rangle = \int_{-\infty}^{+\infty} \phi(p', x) |p'\rangle dp'$  If it were correct then the following would also be correct?  Using the fact that $\langle p | p' \rangle = \delta(p - p')$, $\langle p | x \rangle$ can be computed:  \begin{align} \langle p | x \rangle =&amp; \int_{-\infty}^{+\infty} \phi(p', x) \langle p | p' \rangle dp' \\ =&amp; \int_{-\infty}^{+\infty} \phi(p', x) \delta(p - p') dp' \\ =&amp; \phi(p, x) \\ =&amp; \Large \frac{e^{-ip x/ \hbar}}{\sqrt{2\pi \hbar}} \end{align} as required.  Does the logic work here? From reading the rules it would appear there are two kinds of damage and then straight loss of life:     118.3 If an effect causes a player to gain or lose life, that player's life total is adjusted accordingly.   From reading that I would guess that effects like Extort are not sources of damage. You simply lose the life.      119.2a Damage may be dealt as a result of combat. Each attacking and blocking creature deals combat damage equal to its power during the combat damage step.   So damage from creatures during combat is combat damage.     119.2b Damage may be dealt as an effect of a spell or ability. The spell or ability will specify which object deals that damage.   And that is direct damage from an object.  So the arguments are these:  Does loss of life as outlined by rule 118.3 (at top) count as being dealt damage? Do triggered abilities that redirect or reduce damage effect loss of life?  My second related question: You put  on a  and tap her to deal one damage to your opponent. Am I right in saying that because the damage was direct damage (not dealt during combat) then the triggered ability of preventing the combat phase of the damaged player is not triggered? How can I flush the output of the print function? How do I force Python's print function to output to the screen?