Search Results

Search found 102826 results on 4114 pages for 'question about the problem'.

Page 88/4114 | < Previous Page | 84 85 86 87 88 89 90 91 92 93 94 95  | Next Page >

• simple python file writing question

  - by aharon

  I'm learning Python, and have run into a bit of a problem. On my OSX install of Python 3.1, this happens in the console: >>> filename = "test" >>> reader = open(filename, 'r') >>> writer = open(filename, 'w') >>> reader.read() '' >>> writer.write("hello world\n") 12 >>> reader.read() '' And calling more test in BASH confirms that there is nothing in test. What's going on? Thanks.

  Read the article

• a question on webpage data scraping using Java

  - by Gemma

  Hi there. I am now trying to implement a simple HTML webpage scraper using Java.Now I have a small problem. Suppose I have the following HTML fragment. <div id="sr-h-left" class="sr-comp"> <a class="link-gray-underline" id="compare_header" rel="nofollow" href="javascript:i18nCompareProd('/serv/main/buyer/ProductCompare.jsp?nxtg=41980a1c051f-0942A6ADCF43B802'); " Compare Showing 1 - 30 of 1,439 matches, The data I am interested is the integer 1.439 shown at the bottom.I am just wondering how can I get that integer out of the HTML. I am now considering using a regular expression,and then use the java.util.Pattern to help get the data out,but still not very clear about the process. I would be grateful if you guys could give me some hint or idea on this data scraping. Thanks a lot.

  Read the article

• An update question !

  - by rantravee

  Hi , Here's the problem I'm facing : trying to do my own application update I download the update apk from a web server on the sd card and then I launch the Package Installer with the downloading path ( while the old application is running) . So far after the package installer starts and the user agrees to install the application I get the following message " MyApp Could not be installed on this phone" and in the logcat then following message is printed : "No package identifier when getting value for resource number 0x00000000" . I could not find a reason for this behaviour , so please if there is something that I'm missing do point it to me !

  Read the article

• Question about compilers and how they work

  - by Marin Doric

  This is the C code that frees memory of a singly linked list. It is compiled with Visual C++ 2008 and code works as it should be. /* Program done, so free allocated memory */ current = head; struct film * temp; temp = current; while (current != NULL) { temp = current->next; free(current); current = temp; } But I also encountered ( even in a books ) same code written like this: /* Program done, so free allocated memory */ current = head; while (current != NULL) { free(current); current = current->next; } If I compile that code with my VC++ 2008, program crashes because I am first freeing current and then assigning current-next to current. But obviously if I compile this code with some other complier ( for example, compiler that book author used ) program will work. So question is, why does this code compiled with specific compiler work? Is it because that compiler put instructions in binary file that remember address of current-next although I freed current and my VC++ doesn't. I just want to understand how compilers work.

  Read the article

• I have a question about URI templates in WCF Services

  - by Debby

  I have a web service with following operation contract and my service is hosted at http://localhost:9002/Service.svc/ [OperationContract] [WebGet(UriTemplate = "/Files/{Filepath}")] Stream DownloadFile(string Filepath); This web service would let users download file, if the proper filepath is provided (assuming, I somehow find out that proper filepath). Now, I can access this service from a browser by typing, http://localhost:9002/Service.svc/Files/(Filepath} If {filepath} is some simple string, its not a problem, but I want to send the location of the file. Lets us say users want to download file C:\Test.mp3 on the server. But how can I pass C:\Test.mp3 as {Filepath}? I get an error when I type http://localhost:9002/Service.svc/Files/C:\Test.mp3 in the browser. I am new to web services and find that this community is the quickest way to get answers to my questions.

  Read the article

• Implementation/interface inheritance design question.

  - by Neil G

  I would like to get the stackoverflow community's opinion on the following three design patterns. The first is implementation inheritance; the second is interface inheritance; the third is a middle ground. My specific question is: Which is best? implementation inheritance: class Base { X x() const = 0; void UpdateX(A a) { y_ = g(a); } Y y_; } class Derived: Base { X x() const { return f(y_); } } interface inheritance: class Base { X x() const = 0; void UpdateX(A a) = 0; } class Derived: Base { X x() const { return x_; } void UpdateX(A a) { x_ = f(g(a)); } X x_; } middle ground: class Base { X x() const { return x_; } void UpdateX(A a) = 0; X x_; } class Derived: Base { void UpdateX(A a) { x_ = f(g(a)); } } I know that many people prefer interface inheritance to implementation inheritance. However, the advantage of the latter is that with a pointer to Base, x() can be inlined and the address of x_ can be statically calculated.

  Read the article

• Python - question regarding the concurrent use of `multiprocess`.

  - by orokusaki

  I want to use Python's multiprocessing to do concurrent processing without using locks (locks to me are the opposite of multiprocessing) because I want to build up multiple reports from different resources at the exact same time during a web request (normally takes about 3 seconds but with multiprocessing I can do it in .5 seconds). My problem is that, if I expose such a feature to the web and get 10 users pulling the same report at the same time, I suddenly have 60 interpreters open at the same time (which would crash the system). Is this just the common sense result of using multiprocessing, or is there a trick to get around this potential nightmare? Thanks

  Read the article

• Newbie question: When to use extern "C" { //code } ?

  - by Russel

  Hello, Maybe I'm not understanding the differences between C and C++, but when and why do we need to use: extern "C" { ? Apparently its a "linkage convention"? I read about it briefly and noticed that all the .h header files included with MSVS surround their code with it. What type of code exactly is "C code" and NOT "C++ code"? I thought C++ included all C code? I'm guessing that this is not the case and that C++ is different and that standard features/functions exist in one or the other but not both (ie: printf is C and cout is C++), but that C++ is backwards compatible though the extern "C" declaration. Is this correct? My next question depends on the answer to the first, but I'll ask it here anyway: Since MSVS header files that are written in C are surrounded by extern "C" { ... }, when would you ever need to use this yourself in your own code? If your code is C code and you are trying to compile it in a C++ compiler, shouldn't it work without problem because all the standard h files you include will already have the extern "C" thing in them with the C++ compiler? Do you have to use this when compiling in C++ but linking to alteady built C libraries or something? Please help clarify this for me... Thanks! --Keith

  Read the article

• Java Concurrency in practice sample question

  - by andy boot

  I am reading "Java Concurrency in practice" and looking at the example code on page 51. According to the book this piece of code is at risk of of failure if it has not been published properly. Because I like to code examples and break them to prove how they work. I have tried to make it throw an AssertionError but have failed. (Leading me to my previous question) Can anyone post sample code so that an AssertionError is thrown? Rule: Do not modify the Holder class. public class Holder{ private int n; public Holder(int n){ this.n = n; } public void assertSanity(){ if (n != n) { throw new AssertionError("This statement is false"); } } } I have modified the class to make it more fragile but I still can not get an AssertionError thrown. class Holder2{ private int n; private int n2; public Holder2(int n) throws InterruptedException{ this.n = n; Thread.sleep(200); this.n2 = n; } public void assertSanity(){ if (n != n2) { throw new AssertionError("This statement is false"); } } } Is it possible to make either of the above classes throw an AssertionError? Or do we have to accept that they may occasionally do so and we can't write code to prove it?

  Read the article

• Search SQL Question Between Related Two Tables

  - by mTuran

  Hi, I am writing some kind of search engine for my web application and i have a problem. I have 2 tables first of is projects table: PROJECTS TABLE id int(11) NO PRI NULL auto_increment employer_id int(11) NO MUL NULL project_title varchar(100) NO MUL NULL project_description text NO NULL project_budget int(11) NO NULL project_allowedtime int(11) NO NULL project_deadline datetime NO NULL total_bids int(11) NO NULL average_bid int(11) NO NULL created datetime NO MUL NULL active tinyint(1) NO MUL NULL PROJECTS_SKILLS TABLE project_id int(11) NO MUL NULL skill_id int(11) NO MUL NULL For example: I want ask this query to database: 1-) Skills are 5 and 7. 2-) Order results by created 3-) project title contains "php" word. 4-) Returned rows should contain projects.* columuns. 5-) Projects should be distinct(i don't want same projects in return of query). Please write sql query that ensure these conditions. Thank You.

  Read the article

• Newb Question: scanf() in C

  - by riemannliness

  So I started learning C today, and as an exercise i was told to write a program that asks the user for numbers until they type a 0, then adds the even ones and the odd ones together. Here is is (don't laugh at my bad style): #include <stdio.h>; int main() { int esum = 0, osum = 0; int n, mod; puts("Please enter some numbers, 0 to terminate:"); scanf("%d", &n); while (n != 0) { mod = n % 2; switch(mod) { case 0: esum += n; break; case 1: osum += n; } scanf("%d", &n); } printf("The sum of evens:%d,\t The sum of odds:%d", esum, osum); return 0; } My question concerns the mechanics of the scanf() function. It seems that when you enter several numbers at once separated by spaces (eg. 1 22 34 2 8), the scanf() function somehow remembers each distinct numbers in the line, and steps through the while loop for each one respectively. Why/how does this happen? Example interaction within command prompt: - Please enter some numbers, 0 to terminate: 42 8 77 23 11 (enter) 0 (enter) - The sum of evens:50, The sum of odds:111 I'm running the program through the command prompt, it's compiled for win32 platforms with visual studio.

  Read the article

• rotating circle with swipe question

  - by Joe

  Okay so I'm making something that basically works as a knob, but only half on the screen -- so I just need horizontal swipes to cause it to rotate. I have it nearly all sorted with one exception: if you change direction of your swipe in mid-swipe, the rotation doesn't change direction. I even can see the problem, but not sure what to do about a solution. So in my touchesMoved, I get the swipe into radians in the predictable way: CGFloat radians = atan2f(location.y - centerY, location.x - centerX); I then store radians, add/subtract it to previous rotation and then give the result to the CATransform3D. So the prob is that even though the swipe changes direction, there is a "balance" which doesn't allow an immediate change of direction. Does this make any sense?

  Read the article

• A Newbie question regarding Software Development

  - by Sharif

  Hi, I'm going to complete my B.pharm (Hons.) degree and, you know, I don't have much knowledge about programing. I was wondering to build a software on my own. Could you guys tell me what to learn first for that? Is it too hard for a student of other discipline to build a software? Let me know please. The software I want to make is like a dictionary (or more specifically like "Physician's Desk Reference"). It should find the generic name, company name, indication, price etc. of a drug when I enter the brand name and vice versa. To build a software like that what programing language could help me most and what (and how many) language should I learn first? In my country, there is no practice of Community pharmacy (most of the pharmacy stores are run by unskilled people), that's why this type of thing could help them sell drugs. Would you please tell me what I'm to do and how tough it is? I'm very keen to learn programming. Thanks in advance NB: I started this post in ASKREDDIT section but it seems that was not the right place for poll type question, so I post it again in this section

  Read the article

• Glob() filesearch, question

  - by Peter

  Hi, a little question. I have this code, which is works perfect for files, but If am trying search on a directory name, the result is blank. How I can fix that? <?php function listdirs($dir,$search) { static $alldirs = array(); $dirs = glob($dir."*"); foreach ($dirs as $d){ if(is_file($d)){ $filename = pathinfo($d); if(eregi($search,$filename['filename'])){ print "<a href=http://someurl.com/" . $d .">". $d . "</a><br/>"; } }else{ listdirs($d."/",$search); } } } $path = "somedir/"; $search= "test"; listdirs($path,$search); ?> somedir/test/ result: blank (I want: /somedir/test/) somedir/test/test.txt result: OK I want to search also in the directory names, how I can do that?

  Read the article

• Solr security question

  - by Camran

  I have a linux server, and I am about to upload a classifieds website to it. The website is php based. That means php code adds/removes classifieds, with the help of the users offcourse. The php-code then adds/removes a classified to a database index called Solr (like MySql). Problem is that anybody can currently access the database, but I only want the website to access the database (solr). Solr is on port 8983 as standard btw. My Q is, if I add a rule in my firewall (iptables), to only allow connections coming from the servers IP to the Solr port nr, would this solve my issue? Thanks

  Read the article

• Question regarding ideal database implementation for iPhone app

  - by Jeff

  So I have a question about the ideal setup for an app I am getting ready to build. The app is basically going to be a memorization tool and I already have an sqlite database full of content that I will be using for the app. The user will navigate through the contents of the database(using the uipickerview), and select something for memorization. If that row or cell of data is selected, it is put into a pool or a uitableview that is dedicated to showing which items you have in your "need to memorize" pool. When you go to that tableview, you can select the row, and the actual data would be populated. All information in the tableview would be deletable, in the event that they don't want it there anymore... Thats it. I know that with database interfacing, there are a few different options out there, in this particular setup, is core data the easiest approach? Is there any other way that would be better? I am just kind of looking for a point in the right direction, any help is greatly appreciated!!

  Read the article

• smlnj rephrased question for listdir(filename, directoryname)

  - by czy1985

  i am a newbie learning sml and the question i am thrown with involves IO functions that i have no idea how it works even after reading it. Here is the 2 questions that i really need help with to get me started, please provide me with codings and some explaination, i will be able to trial and error with the code given for the other questions. Q1) listdir(filename,directoryname), which given the name of a directory, list its contents in a text file. The listing is in a form that makes it easy to seperate filenames, dates and sizes from each other. (similar to what msdos does with "dir" but instead of just listing it out, it places all the files and details into a text file. Q2) readlist(filename) which reads a list of filenames (each of which were produced by listdir in (Q1) and combines them into one large list. (reads from the text file in Q1 and then assigning the contents into 1 big list containing all the information) Thing is, i only learned from the lecturer in school on the introduction section, there isnt even a system input or output example shown, not even the "use file" function is taught. if anyone that knows sml sees this, please help. Thanks to anyone who took the effort helping me. Thanks for the reply, current I am using SMLNJ to try and do this. Basically, Q1 requires me to list the directory's files of the "directoryname" provided into a text file in "filename". The Q2 requires me to read from the "filename" text file and then place the contents into one large list. Duplicate of: smlnj listdir

  Read the article

• Design Philosophy Question - When to create new functions

  - by Eclyps19

  This is a general design question not relating to any language. I'm a bit torn between going for minimum code or optimum organization. I'll use my current project as an example. I have a bunch of tabs on a form that perform different functions. Lets say Tab 1 reads in a file with a specific layout, tab 2 exports a file to a specific location, etc. The problem I'm running into now is that I need these tabs to do something slightly different based on the contents of a variable. If it contains a 1 I may need to use Layout A and perform some extra concatenation, if it contains a 2 I may need to use Layout B and do no concatenation but add two integer fields, etc. There could be 10+ codes that I will be looking at. Is it more preferable to create an individual path for each code early on, or attempt to create a single path that branches out only when absolutely required. Creating an individual path for each code would allow my code to be extremely easy to follow at a glance, which in turn will help me out later on down the road when debugging or making changes. The downside to this is that I will increase the amount of code written by calling some of the same functions in multiple places (for example, steps 3, 5, and 9 for every single code may be exactly the same. Creating a single path that would branch out only when required will be a bit messier and more difficult to follow at a glance, but I would create less code by placing conditionals only at steps that are unique. I realize that this may be a case-by-case decision, but in general, if you were handed a previously built program to work on, which would you prefer?

  Read the article

• iPhone/Objective-C struct question my own CGRectZero

  - by Mark

  I am designing a Padding struct as follows: /* Padding. */ struct CGPadding { CGFloat left; CGFloat top; CGFloat right; CGFloat bottom; }; typedef struct CGPadding CGPadding; CG_INLINE CGPadding CGPaddingMake(CGFloat left, CGFloat top, CGFloat right, CGFloat bottom) { CGPadding p; p.left = left; p.top = top; p.right = right; p.bottom = bottom; return p; } This all works perfectly well, the problem is how can I create a const CGPadding CGPaddingZero? If I do like this: const CGPadding CGPaddingZero = (CGPadding){0.0, 0.0, 0.0, 0.0}; It doesnt work. So what am I doing wrong?

  Read the article

• Question regarding C++ Templates

  - by Isuru

  I used a simple class for a test program about templates, this is what I did: template <typename T> class test { public: test<T>::test(); T out(); }; template <typename T> test<T>::test() { } T test<T>::out() { } int main() { //test<int> t; } But when I try to compile it says 'T' : undeclared identifier and use of class template requires template argument list , pointing to the same line, where I have implemented the method out() . Can anyone please explain what the problem is?? I'm using visual studio 2008.

  Read the article

• Mysql Performance Question - Essentially about normalizing efficiency

  - by freqmode

  Hi there. Just a quick question about database performance. I'll outline my site purpose below as background. I'm creating a dictionary site that saves the words users define to a database. What I'm wondering is whether or not to create a words table for each user or to keep one massive words table. This site will be used for entire schools so the single words table would be massive! The database structure is as follows: A user table with: User_ID PRIMARY KEY Username First Last Password Email Country Research Standings SendInfo Donated JoinedOn LastLogin Logins Correct Attempts Admin Active And one word table with: User_ID PRIMARY KEY Word Vocab Spell Defined DefinedAttempted Spelled SpelledAttempted Sentenced SentencedAttempted So what I'm asking is , performance-wise, should I create a new table for each user when they join the site - each user could have hundreds or thousands of words over time? Or is it better to have one massive table with thousands and thousands of records and filter by User_ID. I don't think I'll perform many table joins. My gut feeling is to create a new table for each user, but I thought I'd ask for expert advice! Thanks in advance.

  Read the article

• Odd C interview question

  - by Brennan Vincent

  Hi guys. I found this problem on a site full of interview questions, and was stumped by it. Is there some preprocessor directive that allows one to read from standard input during compilation? Write a small C program, which while compiling takes another program from input terminal, and on running gives the result for the second program. (NOTE: The key is, think UNIX). Suppose, the program is 1.c Then, while compiling $ cc -o 1 1.c int main() { printf("Hello World\n"); } ^D $ ./1 Hello World

  Read the article

• C++ - Resources in static library question

  - by HardCoder1986

  Hello! This isn't a duplicate of http://stackoverflow.com/questions/531502/vc-resources-in-a-static-library because it didn't help :) I have a static library with TWO .rc files in it's project. When I build my project using the Debug configuration, I retrieve the following error (MSVS2008): fatal error LNK1241: resource file res_yyy.res already specified Note, that this happens only in Debug and Release library builds without any troubles. The command line for Resources page in project configuration looks the same for every build: /fo"...(Path here)/Debug/project_name.res" /fo"...(Path here)/Release/project_name.res" and I can't understand what's the trouble. Any ideas? UPDATE I don't know why this happens, but when I turn "Use Link-Time Code Generation" option on the problem goes away. Could somebody explain why does this happen? I feel like MS-compiler is doing something really strange here. Thanks.

  Read the article

• tricky interview question for C++

  - by Alexander

  Given the code below. How would you create/implement SR.h so that it produces the correct output WITHOUT any asterix in your solution? I got bummed by this question #include <cstdio> #include "SR.h" int main() { int j = 5; int a[] = {10, 15}; { SR x(j), y(a[0]), z(a[1]); j = a[0]; a[0] = a[1]; a[1] = j; printf("j = %d, a = {%d, %d}\n", j, a[0], a[1]); } printf("j = %d, a = {%d, %d}\n", j, a[0], a[1]); } //output j = 10, a = {15, 10} j = 5, a = {10, 15} #include <cstdio> #include "SR.h" int main() { int sum = 0; for (int i = 1; i < 100; i++) { SR ii(i); while (i--) sum += i; } printf("sum = %d\n", sum); } //The output is "sum = 161700".

  Read the article

• Simple question C#.net about if else statement

  - by ilkdrl

  Iam doing a simple website and when i press button, i should see weight in label.. i see but if text.maxlenght 6, i should see ERROR message in same label but repeat see weight in label. How can i solve this problem? protected void Button1_Click(object sender, EventArgs e) { double sayi1, sayi2, sayi3, hesap, sonuc; sayi1 = Convert.ToDouble(Tb1.Text); sayi2 = Convert.ToDouble(Tb2.Text); sayi3 = Convert.ToDouble(Tb3.Text); if (Tb1.MaxLength > 6 || Tb2.MaxLength > 6) { lbl1.Text = "ERROR."; } else { hesap = (((sayi1 - ((sayi1 - sayi2) / 2)) * ((sayi1 - sayi2) / 2)) / 40); sonuc = (hesap * sayi3) / 100; lbl1.Text = sonuc.ToString() + "kg"; } }

  Read the article

< Previous Page | 84 85 86 87 88 89 90 91 92 93 94 95  | Next Page >