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  • [python]: path between two nodes

    - by www.yegorov-p.ru
    I'm using networkx to work with graphs. I have pretty large graph (it's near 200 nodes in it) and I try to find all possible paths between two nodes. But, as I understand, networkx can find only shortest path. How can I get not just shortest path, but all possible paths?

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  • Itertools group by functionality

    - by Nil
    I want to group by on dict key >>> x [{'a': 10, 'b': 90}, {'a': 20}, {'a': 30}, {'a': 10}] >>> [(name, list(group)) for name, group in groupby(x, lambda p:p['a'])] [(10, [{'a': 10, 'b': 90}]), (20, [{'a': 20}]), (30, [{'a': 30}]), (10, [{'a': 10}])] This must group on key 10 :(

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  • Store value of os.system or os.popen

    - by chrissygormley
    Hello, I want to grep the error's out of a log file and save the value as an error. When I use: errors = os.system("cat log.txt | grep 'ERROR' | wc -l") I get the return code that the command worked or not. When I use: errors = os.popen("cat log.txt | grep 'ERROR' | wc -l") I get what the command is trying to do. When I run this in the command line I get 3 as thats how many errors there are. Can anyone suggest another way? Thanks

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  • PROLOG all different

    - by inspectorG4dget
    Hello SO, I have a very weird problem with PROLOG. I have used it before, but it's been a while and I'm rusty. I have a list of variables and I need to ensure that none of them are the same. I have tried: use_module(library(bounds)). all_different(A, B, C, D, 6, 8). However, when I try this, I get an error saying that all_different/6 is undefined. How can I go about solving this issue? Is there any library function that I can call directly for this? I am VERY stuck and would greatly appreciate any help. Thanks in advance.

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  • Cabal: Odd Error Message + Lack of Documentation

    - by voxcogitatio
    So I recently installed cabal (from the default binary of ArchLinux). I then tried to upgrade cabal as a user: cabal upgrade Cabal --user --prefix=$USER Resolving dependencies... cabal: fromFlag NoFlag. Use fromFlagOrDefault What I've already done: Googled the error message. Turned up the cabal source and little else. Looked at haskell-wiki on cabal-install. Looked through this guide. So basically I'm wondering: What's up with the error message? Could anyone point me in the direction of a cabal tutorial?

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  • Python 3.1.1 Problem With Tuples

    - by Protean
    This piece of code is supposed to go through a list and preform some formatting to the items, such as removing quotations, and then saving it to another list. class process: def rchr(string_i, asciivalue): string_o = () for i in range(len(string_i)): if ord(string_i[i]) != asciivalue: string_o += string_i[i] return string_o def flist(self, list_i): cache = () cache_list = [] for line in list_i: cache = line.split('\t') cacbe[0] = process.rchr(str(cache[0]), 34) cache_list.append(cache[0]) cache_list[index] = cache index += 1 cache_list.sort() return cache_list p = process() list1a = ['cow', 'dog', '"sheep"'] list1 = p.flist(list1a) print (country_list) However; it chokes at 'string_o += string_i[i]' and gives the following error: Traceback (most recent call last): File "/Projects/Python/safafa.py", line 23, in <module> list1 = p.flist(list1a) File "/Projects/Python/safafa.py", line 14, in flist cacbe[0] = process.rchr(str(cache[0]), 34) File "/Projects/Python/safafa.py", line 7, in rchr string_o += string_i[i] TypeError: can only concatenate tuple (not "str") to tuple

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  • Android Custom View Constructor

    - by Mitch
    I'm learning about using Custom Views from the following: http://developer.android.com/guide/topics/ui/custom-components.html#modifying The description says: Class Initialization As always, the super is called first. Furthermore, this is not a default constructor, but a parameterized one. The EditText is created with these parameters when it is inflated from an XML layout file, thus, our constructor needs to both take them and pass them to the superclass constructor as well. Is there a better description? I've been trying to figure out what the constructor(s) should look like and I've come up with 4 possible choices (see example at end of post). I'm not sure what these 4 choices do (or don't do), why I should implement them, or what the parameters mean. Is there a description of these? Thanks. Mitch public MyCustomView() { super(); } public MyCustomView(Context context) { super(context); } public MyCustomView(Context context, AttributeSet attrs) { super(context, attrs); } public MyCustomView(Context context, AttributeSet attrs, Map params) { super(context, attrs, params); }

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  • Regex: Use start of line/end of line signs (^ or $) in different context

    - by fgysin
    While doing some small regex task I came upon this problem. I have a string that is a list of tags that looks e.g like this: foo,bar,qux,garp,wobble,thud What I needed to do was to check if a certain tag, e.g. 'garp' was in this list. (What it finally matches is not really important, just if there is a match or not.) My first and a bit stupid try at this was to use the following regex: [^,]garp[,$] My idea was that before 'garp' there should either be the start of the line/string or a comma, after 'garp' there should be either a comma or the end of the line/string. Now, it is instantly obvious that this regex is wrong: Both ^ and $ change their behaviour in the context of the character class [ ]. What I finally came up with is the following: ^garp$|^garp,|,garp,|,garp$ This regex just handles the 4 cases one by one. (Tag at beginning of list, in the center, at the end, or as the only element of the list.) The last regex is somehow a bit ugly in my eyes and just for funs sake I'd like to make it a bit more elegant. Is there a way how the start of line/end of line characters (^ and $) can be used in the context of character classes?

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  • In python, what is the fastest way to determine if a string is an email or an integer?

    - by ensnare
    I'd like to be able to pull users from a database using either a supplied e-mail address or the user id (an integer). To do this, I have to detect if the supplied string is an integer, or an e-mail. Looking for the fastest way to do this. Thanks. def __init__(self, data): #populate class data self._fetchInfo(data) def _fetchInfo(self, data): #If an email #SELECT ... WHERE email = 'data' #or if a user_id #SELECT ... WHERE id = 'data' #Fill class attributes self._id = row['id'] self._email = row['id'] ...

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  • How do you handle key down events on Android? I am having issues making it work.

    - by user279112
    For an Android program, I am having trouble handling key down and key up events, and the problem I am having with them can almost certainly be generalized to any sort of user input event. I am using Lunar Lander as one of my main learning devices as I make my first meaningful program, and I noticed that it was using onKeyDown as an overridden method to receive key down events, and it would call one of their more original methods doKeyDown. But when I tried to implement a very small version of my own onKeyDown overide and the actual handler that it calls, it didn't work. I would probably copy and paste my implementations of those two methods, but that doesn't seem to be the problem. You see, I ran the debugger and noticed that they were not getting called - at all. The same goes for my implementations of onKeyUp and the handler that it calls. Something is a little weird here, and when I tried to look at the Android documentation for it, that didn't help at all. I thought that if you had an overide for onKeyDown, then when a key was pressed during execution of the program, onKeyDown would be called as soon as reasonably possible. End of story. But apparently there's something more to it. Apparently you have to do something else somewhere - possibly in the XML when defining the layout or something - to make it work. But I do not know what, and I could not find what in their documentation. What's the secret to this? Thanks!

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  • newbie question -- how does one override show for a newtype?

    - by gatoatigrado
    I want to override the default integer constructors in Haskell so they produce strings (mostly for curiosity, but temporarily to make a nice input alternative for LaTeX's \frac{}{} inconvenience). I wanted to be able to use the language itself, instead of a special parser, but I guess that's probably not going to work out... module Main where import Prelude hiding ((+)) newtype A = A Int deriving (Eq, Show, Num) default (A) (+) :: A -> (A -> String) (A a) + (A b) = (show a) ++ " + " ++ (show b) main2 = 3+4 main :: IO () main = putStrLn main2 The problem with the above is that the + function only works for (A, A) instead of (A, String), etc. If one simply leaves out the pattern match "(A a)" and writes "a" instead, then the show() function prepends "A " so "3" becomes "A 3" instead of just "3". I want to override Show for A, but it seems to be quite a headache...

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  • Java: how to use 3rd-party library?

    - by HH
    $ cat MultiTest.java import com.*; // CODE $ javac Code.java MultiTest.java:1: package com does not exist import com.*; ^ Google Collections Com-dir in the dir where the MultiTest.java -file is located.

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  • Single-player pong game

    - by Jam
    I am just starting out learning pygame and livewires, and I'm trying to make a single-player pong game, where you just hit the ball, and it bounces around until it passes your paddle (located on the left side of the screen and controlled by the mouse), which makes you lose. However, I keep getting the error: "Cannot have more than on Screen object", which I can find no references to online really, and I can't make sense of it. I want to eventually make the game more complicated, but I need to make it work first. Help please! Here's the code so far: from livewires import games games.init(screen_width=640, screen_height=480, fps=50) class Paddle(games.Sprite): image=games.load_image("paddle.bmp") def __init__(self): super(Paddle, self).__init__(image=Paddle.image, y=games.mouse.y, left=0) self.score=games.Text(value=0, size=25, top=5, right=games.screen.width-10) games.screen.add(self.score) def update(self): self.y=games.mouse.y self.check_collide() def check_collide(self): for ball in self.overlapping_sprites: self.score.value+=1 self.score.right=games.screen.width-10 ball.handle_collide() class Ball(games.Sprite): image=games.load_image("ball.bmp") speed=1 def __init__(self, x, y=90): super(Ball, self).__init__(image=Ball.image, x=x, y=y, dx=Ball.speed, dy=Ball.speed) def update(self): if self.left<0: self.end_game() self.destroy() def handle_collide(self): if self.right>games.screen.width: self.dx=-self.dx if self.bottom>games.screen.height or self.top<0: self.dy=-self.dy def ball_destroy(self): self.destroy() def main(): background_image=games.load_image("background.bmp", transparent=False) games.screen.background=background_image the_ball=Ball() games.screen.add(the_ball) the_paddle=Paddle() games.screen.add(the_paddle) games.mouse.is_visible=False games.screen.event_grab=True games.screen.mainloop() main()

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  • Python: x-y-plot with matplotlib

    - by kame
    I want to plot some data. The first column contains the x-data. But matplotlib doesnt plot this. Where is my mistake? #fresnel formula import numpy as np from numpy import cos from scipy import * from pylab import plot, show, ylim, yticks from matplotlib import * from pprint import pprint n1 = 1.0 n2 = 1.5 #alpha, beta, intensity data = [ [10, 22, 4.3], [20, 42, 4.2], [30, 62, 3.6], [40, 83, 1.3], [45, 102, 2.8], [50, 123, 3.0], [60, 143, 3.2], [70, 163, 3.8], ] for i in range(len(data)): rhotang1 = (n1 * cos(data[i][0]) - n2 * cos(data[i][1])) rhotang2 = (n1 * cos(data[i][0]) + n2 * cos(data[i][1])) rhotang = rhotang1 / rhotang2 data[i].append(rhotang) #append 4th value pprint(data) x = data[:][0] y1 = data[:][2] y3 = data[:][3] plot(x, y1, x, y3) show() EDIT: http://paste.pocoo.org/show/205534/ But it doesnt work.

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  • Proper way to set class variables

    - by ensnare
    I'm writing a class to insert users into a database, and before I get too far in, I just want to make sure that my OO approach is clean: class User(object): def setName(self,name): #Do sanity checks on name self._name = name def setPassword(self,password): #Check password length > 6 characters #Encrypt to md5 self._password = password def commit(self): #Commit to database >>u = User() >>u.setName('Jason Martinez') >>u.setPassword('linebreak') >>u.commit() Is this the right approach? Should I declare class variables up top? Should I use a _ in front of all the class variables to make them private? Thanks for helping out.

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  • magento getCollection() can we put where condition?

    - by jarus
    hello , i am working on a magento project and i need to get the value according to country wise like select address where country ="Nepal" can we send the where condition in getCollection() function $collection = Mage::getModel('relocator/location')-getCollection(); any help will be appreciated

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  • Stack / base pointers in assembly

    - by flyingcrab
    I know this topic has been covered ad-naseum here, and other places on the internet - but hopefully the question is a simple one as I try to get my head around assembly... So if i understand correctly the ebp (base pointer) will point to the top of the stack, and the esp (stack pointer) will point to the bottom -- since the stack grows downward. esp therefore points to the 'current location'. So on a function call, once you've saved the ebp on the stack you insert a new stack frame - for the function. So in the case of the image below, if you started from N-3 you would go to N-2 with a function call. But when you are at N-2 - is your ebp == 25 and the esp == 24 (at least initially, before any data is placed on the stack)? Is this correct or am I of on a tangent here? Thanks!

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  • How to build a java applet?

    - by Stefano Borini
    Most of the tutorials around explain how to create a java applet: create a .java file with a class, compile it with javac, put the .class somewhere, add a proper tag in the html. However, I'm not able to find anything about the best practices to build and release a complex applet, made of multiple classes and with additional libraries. How is the build/release process for this case ? What is it needed to go from my java project to the final .jar to put on the web ? I'm working with pure Eclipse, no plugins.

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  • how to extract elements from a list in python ?

    - by Stefano Borini
    I feel suddenly uneasy of not being able to perform this operation easily. It could be that I'm tired, or that there's really no way (google didn't help), but... if you have a list in python, and want to extract element at indices say 1, 2 and 5 into a new list, how do you do ? This is how I did it, but I'm not very satisfied >>> a [10, 11, 12, 13, 14, 15] >>> [x[1] for x in enumerate(a) if x[0] in [1,2,5]] [11, 12, 15] any better way ? more in general, given a tuple with indices, how to use this tuple to extract the corresponding elements from a list, eventually with duplication (e.g. tuple (1,1,2,1,5) produces [11,11,12,11,15] )

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  • Which language/framework to use for this desktop internet application?

    - by Karsten
    I'd like to experiment with a new language/framework to work on some desktop tools for myself, which will do tasks related to internet services. I.e. i'd like to to monitor some of my servers for http or icmp response, also parse xml responses. I have experience with php, lua, mysql, and basic knowledge of java and c++. I'm also interested in exploring multithreading for this, background tasks and a responsive gui do need that as i have read. Being a private project, i certainly want to learn something new, but i don't have that much free time. The question for you would be which language and what framework to choose that could help me with this tasks: lightweight + fast gui (windows only would be ok, platform-independent even better) network/socket support, html module would be appreciated htmlview support xml "parsing" support (xpath or something like the phpish DOMDocument class) threading support Free software would be nice, but paying some bucks won't hurt me if it really helps the case.

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  • PHP: Loop or no loop?

    - by Joseph Robidoux
    In this situation, is it better to use a loop or not? echo "0"; echo "1"; echo "2"; echo "3"; echo "4"; echo "5"; echo "6"; echo "7"; echo "8"; echo "9"; echo "10"; echo "11"; echo "12"; echo "13"; or $number = 0; while ($number != 13) { echo $number; $number = $number + 1; }

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  • Blackjack game reshuffling problem-edited

    - by Jam
    I am trying to make a blackjack game where before each new round, the program checks to make sure that the deck has 7 cards per player. And if it doesn't, the deck clears, repopulates, and reshuffles. I have most of the problem down, but for some reason at the start of every deal it reshuffles the deck more than once, and I can't figure out why. Help, please. Here's what I have so far: (P.S. the imported cards and games modules aren't part of the problem, I'm fairly sure my problem lies in the deal() function of my BJ_Deck class.) import cards, games class BJ_Card(cards.Card): """ A Blackjack Card. """ ACE_VALUE = 1 def get_value(self): if self.is_face_up: value = BJ_Card.RANKS.index(self.rank) + 1 if value > 10: value = 10 else: value = None return value value = property(get_value) class BJ_Deck(cards.Deck): """ A Blackjack Deck. """ def populate(self): for suit in BJ_Card.SUITS: for rank in BJ_Card.RANKS: self.cards.append(BJ_Card(rank, suit)) def deal(self, hands, per_hand=1): for rounds in range(per_hand): if len(self.cards)>=7*(len(hands)): print "Reshuffling the deck." self.cards=[] self.populate() self.shuffle() for hand in hands: top_card=self.cards[0] self.give(top_card, hand) class BJ_Hand(cards.Hand): """ A Blackjack Hand. """ def __init__(self, name): super(BJ_Hand, self).__init__() self.name = name def __str__(self): rep = self.name + ":\t" + super(BJ_Hand, self).__str__() if self.total: rep += "(" + str(self.total) + ")" return rep def get_total(self): # if a card in the hand has value of None, then total is None for card in self.cards: if not card.value: return None # add up card values, treat each Ace as 1 total = 0 for card in self.cards: total += card.value # determine if hand contains an Ace contains_ace = False for card in self.cards: if card.value == BJ_Card.ACE_VALUE: contains_ace = True # if hand contains Ace and total is low enough, treat Ace as 11 if contains_ace and total <= 11: # add only 10 since we've already added 1 for the Ace total += 10 return total total = property(get_total) def is_busted(self): return self.total > 21 class BJ_Player(BJ_Hand): """ A Blackjack Player. """ def is_hitting(self): response = games.ask_yes_no("\n" + self.name + ", do you want a hit? (Y/N): ") return response == "y" def bust(self): print self.name, "busts." self.lose() def lose(self): print self.name, "loses." def win(self): print self.name, "wins." def push(self): print self.name, "pushes." class BJ_Dealer(BJ_Hand): """ A Blackjack Dealer. """ def is_hitting(self): return self.total < 17 def bust(self): print self.name, "busts." def flip_first_card(self): first_card = self.cards[0] first_card.flip() class BJ_Game(object): """ A Blackjack Game. """ def __init__(self, names): self.players = [] for name in names: player = BJ_Player(name) self.players.append(player) self.dealer = BJ_Dealer("Dealer") self.deck = BJ_Deck() self.deck.populate() self.deck.shuffle() def get_still_playing(self): remaining = [] for player in self.players: if not player.is_busted(): remaining.append(player) return remaining # list of players still playing (not busted) this round still_playing = property(get_still_playing) def __additional_cards(self, player): while not player.is_busted() and player.is_hitting(): self.deck.deal([player]) print player if player.is_busted(): player.bust() def play(self): # deal initial 2 cards to everyone self.deck.deal(self.players + [self.dealer], per_hand = 2) self.dealer.flip_first_card() # hide dealer's first card for player in self.players: print player print self.dealer # deal additional cards to players for player in self.players: self.__additional_cards(player) self.dealer.flip_first_card() # reveal dealer's first if not self.still_playing: # since all players have busted, just show the dealer's hand print self.dealer else: # deal additional cards to dealer print self.dealer self.__additional_cards(self.dealer) if self.dealer.is_busted(): # everyone still playing wins for player in self.still_playing: player.win() else: # compare each player still playing to dealer for player in self.still_playing: if player.total > self.dealer.total: player.win() elif player.total < self.dealer.total: player.lose() else: player.push() # remove everyone's cards for player in self.players: player.clear() self.dealer.clear() def main(): print "\t\tWelcome to Blackjack!\n" names = [] number = games.ask_number("How many players? (1 - 7): ", low = 1, high = 8) for i in range(number): name = raw_input("Enter player name: ") names.append(name) print game = BJ_Game(names) again = None while again != "n": game.play() again = games.ask_yes_no("\nDo you want to play again?: ") main() raw_input("\n\nPress the enter key to exit.") Since someone decided to call this 'psychic-debugging', I'll go ahead and tell you what the modules are then. Here's the cards module: class Card(object): """ A playing card. """ RANKS = ["A", "2", "3", "4", "5", "6", "7", "8", "9", "10", "J", "Q", "K"] SUITS = ["c", "d", "h", "s"] def __init__(self, rank, suit, face_up = True): self.rank = rank self.suit = suit self.is_face_up = face_up def __str__(self): if self.is_face_up: rep = self.rank + self.suit else: rep = "XX" return rep def flip(self): self.is_face_up = not self.is_face_up class Hand(object): """ A hand of playing cards. """ def init(self): self.cards = [] def __str__(self): if self.cards: rep = "" for card in self.cards: rep += str(card) + "\t" else: rep = "<empty>" return rep def clear(self): self.cards = [] def add(self, card): self.cards.append(card) def give(self, card, other_hand): self.cards.remove(card) other_hand.add(card) class Deck(Hand): """ A deck of playing cards. """ def populate(self): for suit in Card.SUITS: for rank in Card.RANKS: self.add(Card(rank, suit)) def shuffle(self): import random random.shuffle(self.cards) def deal(self, hands, per_hand = 1): for rounds in range(per_hand): for hand in hands: if self.cards: top_card = self.cards[0] self.give(top_card, hand) else: print "Can't continue deal. Out of cards!" if name == "main": print "This is a module with classes for playing cards." raw_input("\n\nPress the enter key to exit.") And here's the games module: class Player(object): """ A player for a game. """ def __init__(self, name, score = 0): self.name = name self.score = score def __str__(self): rep = self.name + ":\t" + str(self.score) return rep def ask_yes_no(question): """Ask a yes or no question.""" response = None while response not in ("y", "n"): response = raw_input(question).lower() return response def ask_number(question, low, high): """Ask for a number within a range.""" response = None while response not in range(low, high): response = int(raw_input(question)) return response if name == "main": print "You ran this module directly (and did not 'import' it)." raw_input("\n\nPress the enter key to exit.")

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  • OpenCV - DLL missing, but it's not?

    - by charles-22
    I am trying just a basic program with OpenCV with the following code: #include "cv.h" #include "highgui.h" int main() { IplImage* newImg; newImg = cvLoadImage("~/apple.bmp", 1); cvNamedWindow("Window", 1); cvShowImage("Window", newImg); cvWaitKey(0); cvDestroyWindow("Window"); cvReleaseImage(&newImg); return 0; } When I run this, I get The program can't start because libcxcore200.dll is missing from your computer. Try reinstalling the program to fix this problem. However, I can see this DLL. It exists. I have added the following to the input dependencies for my linker C:\OpenCV2.0\lib\libcv200.dll.a C:\OpenCV2.0\lib\libcvaux200.dll.a C:\OpenCV2.0\lib\libcxcore200.dll.a C:\OpenCV2.0\lib\libhighgui200.dll.a What gives? I'm using visual studio 2008.

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