Search Results

Search found 10295 results on 412 pages for 'rails beginner'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 199/412 | < Previous Page | 195 196 197 198 199 200 201 202 203 204 205 206  | Next Page >

  • How do I use "this" in a member function?

    - by Peter Stewart
    I've written a member function of class Node to read a tree of Nodes in postfix order. It will be called by the Node instance which is the root node of the tree. So: N.postfix(); these appear to be illeagal: *this->left.postfix(); *this->right.postfix(); What is the proper way to do this? class Node { public: const char *cargo; int depth; Node *left; Node *right void Node::postfix() { if (this==__nullptr) { return; } else { *this->left.postfix(); *this->right.postfix(); out<<*this->cargo<<"\n"; return; } };

    Read the article

  • How can I "override" deepcopy in Python?

    - by Az
    Hi there, I'd like to override __deepcopy__ for a given SQLAlchemy-mapped class such that it ignores any SQLA attributes but deepcopies everything else that's part of the class. I'm not particularly familiar with overriding any of Python's built-in objects in particular but I've got some idea as to what I want. Let's just make a very simple class User that's mapped using SQLA. class User(object): def __init__(self, user_id, name): self.user_id = user_id self.name = name I've used dir() to see, before and after mapping, what SQLAlchemy-specific attributes there are and I've found _sa_class_manager and _sa_instance_state. Provided those are the only ones how would I ignore that when defining __deepcopy__? Also, are there any attributes the SQLA injects into the mapped object? (I asked this in a previous question (as an edit a few days after I selected an answer to the main question, though) but I think I missed the train there. Apologies for that.)

    Read the article

  • How to convert list into a string?

    - by PARIJAT
    I have extracted some data from the file and want to write it in the file 2 but the program says 'sequence item 1: expected string, list found', I want to know how I can convert buffer[] i.e. string into sequence, so that it could be saved in file 2. file = open('/ddfs/user/data/k/ktrip_01/hmm.txt','r') file2 = open('/ddfs/user/data/k/ktrip_01/hmm_write.txt','w') buffer = [] rec = file.readlines() for line in rec : field = line.split() print '>',field[0] term = field[0] buffer.append(term) print field[1], field[2], field[6], field[12] term1 = field [1] buffer.append(term1) term2 = field[2] buffer.append[term2] term3 = field[6] buffer.append[term3] term4 = field[12] buffer.append[term4] file2.write(buffer) file.close() file2.close()

    Read the article

  • What is the best way to learn VB/VBA?

    - by Noah
    I have wanted to learn VB and VBA for a long time. My school offers a coarse, but it doesn't fit with the rest of my schedule. It will be my first programing language. I was considering using the textbook my school uses (An introduction to programing using visual basic 2008, but I wold get the 2010 version), but I was wondering if there were better resources I could use. I mainly want to lean to learn VBA so I cam create macros and other tools for MS Word. Please understand that this is the fist time I will be programming and I am teaching myself (with the books/online resources).

    Read the article

  • Python - from file to data structure?

    - by Seafoid
    Hi, I have large file comprising ~100,000 lines. Each line corresponds to a cluster and each entry within each line is a reference i.d. for another file (protein structure in this case), e.g. 1hgn 1dju 3nmj 8kfn 9opu 7gfb 4bui I need to read in the file as a list of lists where each line is a sublist, thus preserving the integrity of the cluster, e.g. nested_list = [['1hgn', '1dju', '3nmj', '8kfn'], ['9opu', '7gfb'], ['4bui']] My current code creates a nested list but the entries within each list are a single string and not comma separated. Therefore, I cannot splice the list with indices so easily. Any help greatly appreciated. Thanks, S :-)

    Read the article

  • A general question about compilation and interpretation.

    - by wucnuc
    Hi stackoverflow, I apologize in advance for the possible stupidity of this question. However, the following has been the source of some confusion for me and I know the people here will be able to handily clear up the confusion for me. Basically, I would like to finally understand the relationship between any and all of the following terms. Some of the terms I do actually understand pretty well, but some of them are similar in my mind and I would like to once and for all to see their relationships/distinctions laid out all at once. They are: compiler interpreter bytecode machine code assembler assembly language binary object code executable Ideally, an answer would use examples from Java and C++ and other well-known programming languages that a young-ish student like me would be familiar with. Also, if you want to throw in any other useful terms that would be fine too :)

    Read the article

  • Generics List Interface...newb question

    - by newToProgramming
    The List interface is the following: public interface List<E>{ public boolean add(Object e); public boolean remove(Object e); public boolean contains(Object e); ...etc Why aren't the add, remove and contains methods written like the following? public boolean add(E e) public boolean remove(E e) public boolean contains(E e)

    Read the article

  • How do Arrays work in C#?

    - by Slateboard
    I know that they are used to store data, but I have a difficult time understanding exactly how to use them in a program. In addition, I found this site with a tetris clone tutorial (the actual tutorial is missing). It uses arrays, but I can't really make sense of how it works. Here's an example of the code - public int[, ,] TShape = new int[4, 4, 2] { {{1, 0}, {0, 1}, {1, 1}, {2, 1}}, {{1, 0}, {0, 1}, {1, 1}, {1, 2}}, {{0, 0}, {1, 0}, {2, 0}, {1, 1}}, {{0, 0}, {0, 1}, {1, 1}, {0, 2}}}; Could it be that I'm looking too hard into this, or perhaps there's something I'm not grasping about it?

    Read the article

  • Which MS technologies would be suited for a data intensive application?

    - by steve.tse
    I'm a junior VB.net developer with little application design knowledge. I've been reading a lot of material online regarding different design patterns, frameworks, and methodologies. It's become a bit confusing for me. Right now I'm trying to decide on what language would be best suited to convert an existing VB6 application (with SQL server backend.) I need to update the UI and add more user functionality and reporting capabilities. Initially I was thinking of using WPF and attempting the MVVM model for this big project. Reports would be generated from SSRS. A peer suggested using ASP.net and I don't have enough experience to determine what would be better. The senior programmers here are stuck on using VB6 and don't have any input on what to use. They are encouraging me to use the latest technologies. This application would be for ~20 users in a central location. Ideally I would stick to a Microsoft .net language. Current interface is similar to a datagrid table where the user would click in to see the detail of each record. They would need to have multiple records open at any given time. I look forward to all the advice I can get. EDIT 2010/04/22 2:47 PM EST What is your audience? Internal clients within an intranet How complex are the interactions you expect to implement? not very... displaying data from SQL server to UI. Allow user updates to said data. Typically just one user modifying a record. Do you require near real-time data updates? no How often do you expect to update the application after the first release? twice/year Do you expect a well-defined set of client platforms? Yes, windows xp environment, potentially upgrading to Win7. Currently in IE.6 moving to IE7 or 8 within a couple of months. Do users need access from anywhere? No, just from their PC.

    Read the article

  • How do you keep application logic separate from UI when UI components have built-in functionality?

    - by Al C
    I know it's important to keep user interface code separated from domain code--the application is easier to understand, maintain, change, and (sometimes) isolate bugs. But here's my mental block ... Delphi comes with components with methods that do what I want, e.g., a RichText Memo component lets me work with rich text. Other components, like TMS's string grid not only do what I want, but I paid extra for the functionality. These features put the R in RAD. It seems illogical to write my own classes to do things somebody else has already done for me. It's reinventing the wheel [ever tried working directly with rich text? :-) ] But if I use the functionality built into components like these, then I will end up with lots of intermingled UI and domain code--I'll have a form with most of my code built into its event handlers. How do you deal with this issue? ... Or, if I want to continue using the code others have already written for me, how would you suggest I deal with the issue?

    Read the article

  • Java method: retrieve the inheriting type

    - by DrDro
    I have several classes that extend C and I would need a method that accepts any argument of type C. But in this method I would like to know if I'm dealing with A or B. * public A extends C public B extends C public void goForIt(C c)() If I cast how can I retrieve the type in a clean way (I just read using getClass or instanceof is often not the best way). *Sorry but I can't type closing braces

    Read the article

  • How to handle array element between int and Integer

    - by masato-san
    First, it is long post so if you need clarification please let me know. I'm new to Java and having difficulty deciding whether I should use int[] or Integer[]. I wrote a function that find odd_number from int[] array. public int[] find_odd(int[] arr) { int[] result = new int[arr.length]; for(int i=0; i<arr.length; i++) { if(arr[i] % 2 != 0) { //System.out.println(arr[i]); result[i] = arr[i]; } } return result; } Then, when I pass the int[] array consisting of some integer like below: int[] myArray = {-1, 0, 1, 2, 3}; int[] result = find_odd(myArray); The array "result" contains: 0, -1, 0, 1, 0, 3 Because in Java you have to define the size of array first, and empty int[] array element is 0 not null. So when I want to test the find_odd() function and expect the array to have odd numbers (which it does) only, it throws the error because the array also includes 0s representing "empty cell" as shown above. My test code: public void testFindOddPassValidIntArray() { int[] arr = {-2, -1, 0, 1, 3}; int[] result = findOddObj.find_odd(arr); //check if return array only contain odd number for(int i=0; i<result.length; i++) { if(result[i] != null) { assert is_odd(result[i]) : result[i]; } } } So, my question is should I use int[] array and add check for 0 element in my test like: if(result[i] != 0) { assert is_odd(result[i] : result[i] } But in this case, if find_odd() function is broken and returning 0 by miscalculation, I can't catch it because my test code would only assume that 0 is empty cell. OR should I use Integer[] array whose default is null? How do people deal with this kind of situation?

    Read the article

  • PHP - Filter some words

    - by bob
    I want to filter some reserved word on my title form. $adtitle = sanitize($_POST['title']); $ignore = array('sale','buy','rent'); if(in_array($adtitle, $ignore)) { $_SESSION['ignore_error'] = '<strong>'.$adtitle.'</strong> cannot be use as your title'; header('Location:/submit/'); exit; How to make something like this. If user type Car for sale the sale will detected as reserved keyword. Now my current code only detect single keyword only.

    Read the article

  • In what order should the Python concepts be explained to absolute beginners?

    - by Tomaž Pisanski
    I am teaching Python to undergraduate math majors. I am interested in the optimal order in which students should be introduced to various Python concepts. In my view, at each stage the students should be able to solve a non-trivial programming problem using only the tools available at that time. Each new tool should enable a simpler solution to a familiar problem. A selection of numerous concepts available in Python is essential in order to keep students focused. They should also motivated and should appreciate each newly mastered tool without too much memorization. Here are some specific questions: For instance, my predecessor introduced lists before strings. I think the opposite is a better solution. Should function definitions be introduced at the very beginning or after mastering basic structured programming ideas, such as decisions (if) and loops (while)? Should sets be introduced before dictionaries? Is it better to introduce reading and writing files early in the course or should one use input and print for most of the course? Any suggestions with explanations are most welcome.

    Read the article

  • How do I splice a python string programmatically?

    - by Robin Welch
    Very simple question, hopefully. So, in Python you can split up strings using indices as follows: >>> a="abcdefg" >>> print a[2:4] cd but how do you do this if the indices are based on variables? E.g. >>> j=2 >>> h=4 >>> print a[j,h] Traceback (most recent call last): File "<stdin>", line 1, in ? TypeError: string indices must be integers

    Read the article

  • I'm having a problem identifying a floating point exception.

    - by Peter Stewart
    I'm using c++ in visual studio express to generate random expression trees for use in a genetic algorithm type of program. Because they are random, the trees often generate (I'll call them exceptions, I'm not sure what they are) Thanks to a suggestion by George, I turned the mask _MCW_EM on so that hardware interrupts are turned off. (the default) So, the program runs uninterrupted, but some of the values returned are: -1.#INF, -1.#NAN, -1.#INV. I don't know how to identify these so that I can throw an exeption: if ( variable == -1.#INF) ?? DigitalRoss in this post seemed to have the solution, but as I understood it I couldn't make it work. I've been looking all over the place for this simple bit of code, that I assumed would be used all the time, but have had no luck. thanks

    Read the article

  • As a PHP developer thinking of making Perl a secondary strong suit, what do I need to know?

    - by Hexagon Theory
    I consider myself quite fluent in PHP and am rather familiar with nearly all of the important aspects and uses, as well as its pratfalls. This in mind, I think the major problem in taking on Perl is going to be with the syntax. Aside from this (a minor hindrance, really, as I'm rather sold on the fact that Perl's is far more readable), what are some key differences you think I should make myself aware of prior to taking on the language?

    Read the article

  • media.set_xx giving me grief!

    - by Firas
    New guy here. I asked a while back about a sprite recolouring program that I was having difficulty with and got some great responses. Basically, I tried to write a program that would recolour pixels of all the pictures in a given folder from one given colour to another. I believe I have it down, but, now the program is telling me that I have an invalid value specified for the red component of my colour. (ValueError: Invalid red value specified.), even though it's only being changed from 64 to 56. Any help on the matter would be appreciated! (Here's the code, in case I messed up somewhere else; It's in Python): import os import media import sys def recolour(old, new, folder): old_list = old.split(' ') new_list = new.split(' ') folder_location = os.path.join('C:\', 'Users', 'Owner', 'Spriting', folder) for filename in os.listdir (folder): current_file = media.load_picture(folder_location + '\\' + filename) for pix in current_file: if (media.get_red(pix) == int(old_list[0])) and \ (media.get_green(pix) == int(old_list[1])) and \ (media.get_blue(pix) == int(old_list[2])): media.set_red(pix, new_list[0]) media.set_green(pix, new_list[1]) media.set_blue(pix, new_list[2]) media.save(pic) if name == 'main': while 1: old = str(raw_input('Please insert the original RGB component, separated by a single space: ')) if old == 'quit': sys.exit(0) new = str(raw_input('Please insert the new RGB component, separated by a single space: ')) if new == 'quit': sys.exit(0) folder = str(raw_input('Please insert the name of the folder you wish to modify: ')) if folder == 'quit': sys.exit(0) else: recolour(old, new, folder)

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 195 196 197 198 199 200 201 202 203 204 205 206  | Next Page >