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  • why does b'(and sometimes b' ') show up when I split some HTML source[Python]

    - by Oliver
    I'm fairly new to Python and programming in general. I have done a few tutorials and am about 2/3 through a pretty good book. That being said I've been trying to get more comfortable with Python and proggramming by just trying things in the std lib out. that being said I have recently run into a wierd quirk that I'm sure is the result of my own incorrect or un-"pythonic" use of the urllib module(with Python 3.2.2) import urllib.request HTML_source = urllib.request.urlopen(www.somelink.com).read() print(HTML_source) when this bit is run through the active interpreter it returns the HTML source of somelink, however it prefixes it with b' for example b'<HTML>\r\n<HEAD> (etc). . . . if I split the string into a list by whitespace it prefixes every item with the b' I'm not really trying to accomplish something specific just trying to familiarize myself with the std lib. I would like to know why this b' is getting prefixed also bonus -- Is there a better way to get HTML source WITHOUT using a third party module. I know all that jazz about not reinventing the wheel and what not but I'm trying to learn by "building my own tools" Thanks in Advance!

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  • How to create Python module distribution to gracefully fall-back to pure Python code

    - by Craig McQueen
    I have written a Python module, and I have two versions: a pure Python implementation and a C extension. I've written the __init__.py file so that it tries to import the C extension, and if that fails, it imports the pure Python code (is that reasonable?). Now, I'd like to know what is the best way to distribute this module (e.g. write setup.py) so it can be easily used by people with or without the facility to build, or use, the C extension. My experience is limited but I see two possible cases: User does not have MS Visual Studio, or the GCC compiler suite, installed on their machine, to build the C extension User is running IronPython, Jython, or anything other than CPython. I only have used CPython. So I'm not sure how I could distribute this module so that it would work smoothly and be easy to install on those platforms, if they're unable to use the C extension.

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  • Python 2 vs Python 3 and Tutorial

    - by MR-J
    Hey guys. I am 12 years old and I have had a small amount of experience with BASIC. I am thinking about learning Python, but I’m not sure if I should learn the 2.6 version or the 3.0 version. I don’t really care about the support for libraries or anything along those lines quite yet. I was wondering if it is easier to code in 3.0 than 2.6. And is it more fun and productive? I would also appreciate it if you could point me in the right direction for a simple yet complete tutorial that is easy to understand and possible teaches Object Oriented Programing. I don’t really care if it teaches OOP or not. One more thing; if I do learn python, is it possible to easily compile a python source code file into a 'stand-alone' .exe file for Windows? I really liked that functionality in BASIC. Thanks!!!!

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  • how to build a index table(python dict like) in python with sqlite3

    - by Registered User KC
    Suppose I have one string list may have duplicated items: A B C A A C D E F F I want to make a list can assign an unique index for each item, looks like: 1 A 2 B 3 C 4 D 5 E 6 F now I created sqlite3 database with below SQL statement: CREATE TABLE aa ( myid INTEGER PRIMARY KEY AUTOINCREMENT, name STRING, UNIQUE (myid) ON CONFLICT FAIL, UNIQUE (name) ON CONFLICT FAIL); The plan is insert each row into the database in python. My question is how to handle the error when conflict do happened when insert in python module sqlite3? For example: the program will printing a warning message which item is conflicted and continue next insert action when inserting in python? Thanks

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  • Python script is exiting with no output and I have no idea why

    - by Adam Tuttle
    I'm attempting to debug a Subversion post-commit hook that calls some python scripts. What I've been able to determine so far is that when I run post-commit.bat manually (I've created a wrapper for it to make it easier) everything succeeds, but when SVN runs it one particular step doesn't work. We're using CollabNet SVNServe, which I know from the documentation removes all environment variables. This had caused some problems earlier, but shouldn't be an issue now. Before Subversion calls a hook script, it removes all variables - including $PATH on Unix, and %PATH% on Windows - from the environment. Therefore, your script can only run another program if you spell out that program's absolute name. The relevant portion of post-commit.bat is: echo -------------------------- >> c:\svn-repos\company\hooks\svn2ftp.out.log set SITENAME=staging set SVNPATH=branches/staging/wwwroot/ "C:\Python3\python.exe" C:\svn-repos\company\hooks\svn2ftp.py ^ --svnUser="svnusername" ^ --svnPass="svnpassword" ^ --ftp-user=ftpuser ^ --ftp-password=ftppassword ^ --ftp-remote-dir=/ ^ --access-url=svn://10.0.100.6/company ^ --status-file="C:\svn-repos\company\hooks\svn2ftp-%SITENAME%.dat" ^ --project-directory=%SVNPATH% "staging.company.com" %1 %2 >> c:\svn-repos\company\hooks\svn2ftp.out.log echo -------------------------- >> c:\svn-repos\company\hooks\svn2ftp.out.log When I run post-commit.bat manually, for example: post-commit c:\svn-repos\company 12345, I see output like the following in svn2ftp.out.log: -------------------------- args1: c:\svn-repos\company args0: staging.company.com abspath: c:\svn-repos\company project_dir: branches/staging/wwwroot/ local_repos_path: c:\svn-repos\company getting youngest revision... done, up-to-date -------------------------- However, when I commit something to the repo and it runs automatically, the output is: -------------------------- -------------------------- svn2ftp.py is a bit long, so I apologize but here goes. I'll have some notes/disclaimers about its contents below it. #!/usr/bin/env python """Usage: svn2ftp.py [OPTION...] FTP-HOST REPOS-PATH Upload to FTP-HOST changes committed to the Subversion repository at REPOS-PATH. Uses svn diff --summarize to only propagate the changed files Options: -?, --help Show this help message. -u, --ftp-user=USER The username for the FTP server. Default: 'anonymous' -p, --ftp-password=P The password for the FTP server. Default: '@' -P, --ftp-port=X Port number for the FTP server. Default: 21 -r, --ftp-remote-dir=DIR The remote directory that is expected to resemble the repository project directory -a, --access-url=URL This is the URL that should be used when trying to SVN export files so that they can be uploaded to the FTP server -s, --status-file=PATH Required. This script needs to store the last successful revision that was transferred to the server. PATH is the location of this file. -d, --project-directory=DIR If the project you are interested in sending to the FTP server is not under the root of the repository (/), set this parameter. Example: -d 'project1/trunk/' This should NOT start with a '/'. 2008.5.2 CKS Fixed possible Windows-related bug with tempfile, where the script didn't have permission to write to the tempfile. Replaced this with a open()-created file created in the CWD. 2008.5.13 CKS Added error logging. Added exception for file-not-found errors when deleting files. 2008.5.14 CKS Change file open to 'rb' mode, to prevent Python's universal newline support from stripping CR characters, causing later comparisons between FTP and SVN to report changes. """ try: import sys, os import logging logging.basicConfig( level=logging.DEBUG, format='%(asctime)s %(levelname)s %(message)s', filename='svn2ftp.debug.log', filemode='a' ) console = logging.StreamHandler() console.setLevel(logging.ERROR) logging.getLogger('').addHandler(console) import getopt, tempfile, smtplib, traceback, subprocess from io import StringIO import pysvn import ftplib import inspect except Exception as e: logging.error(e) #capture the location of the error frame = inspect.currentframe() stack_trace = traceback.format_stack(frame) logging.debug(stack_trace) print(stack_trace) #end capture sys.exit(1) #defaults host = "" user = "anonymous" password = "@" port = 21 repo_path = "" local_repos_path = "" status_file = "" project_directory = "" remote_base_directory = "" toAddrs = "[email protected]" youngest_revision = "" def email(toAddrs, message, subject, fromAddr='[email protected]'): headers = "From: %s\r\nTo: %s\r\nSubject: %s\r\n\r\n" % (fromAddr, toAddrs, subject) message = headers + message logging.info('sending email to %s...' % toAddrs) server = smtplib.SMTP('smtp.company.com') server.set_debuglevel(1) server.sendmail(fromAddr, toAddrs, message) server.quit() logging.info('email sent') def captureErrorMessage(e): sout = StringIO() traceback.print_exc(file=sout) errorMessage = '\n'+('*'*80)+('\n%s'%e)+('\n%s\n'%sout.getvalue())+('*'*80) return errorMessage def usage_and_exit(errmsg): """Print a usage message, plus an ERRMSG (if provided), then exit. If ERRMSG is provided, the usage message is printed to stderr and the script exits with a non-zero error code. Otherwise, the usage message goes to stdout, and the script exits with a zero errorcode.""" if errmsg is None: stream = sys.stdout else: stream = sys.stderr print(__doc__, file=stream) if errmsg: print("\nError: %s" % (errmsg), file=stream) sys.exit(2) sys.exit(0) def read_args(): global host global user global password global port global repo_path global local_repos_path global status_file global project_directory global remote_base_directory global youngest_revision try: opts, args = getopt.gnu_getopt(sys.argv[1:], "?u:p:P:r:a:s:d:SU:SP:", ["help", "ftp-user=", "ftp-password=", "ftp-port=", "ftp-remote-dir=", "access-url=", "status-file=", "project-directory=", "svnUser=", "svnPass=" ]) except getopt.GetoptError as msg: usage_and_exit(msg) for opt, arg in opts: if opt in ("-?", "--help"): usage_and_exit() elif opt in ("-u", "--ftp-user"): user = arg elif opt in ("-p", "--ftp-password"): password = arg elif opt in ("-SU", "--svnUser"): svnUser = arg elif opt in ("-SP", "--svnPass"): svnPass = arg elif opt in ("-P", "--ftp-port"): try: port = int(arg) except ValueError as msg: usage_and_exit("Invalid value '%s' for --ftp-port." % (arg)) if port < 1 or port > 65535: usage_and_exit("Value for --ftp-port must be a positive integer less than 65536.") elif opt in ("-r", "--ftp-remote-dir"): remote_base_directory = arg elif opt in ("-a", "--access-url"): repo_path = arg elif opt in ("-s", "--status-file"): status_file = os.path.abspath(arg) elif opt in ("-d", "--project-directory"): project_directory = arg if len(args) != 3: print(str(args)) usage_and_exit("host and/or local_repos_path not specified (" + len(args) + ")") host = args[0] print("args1: " + args[1]) print("args0: " + args[0]) print("abspath: " + os.path.abspath(args[1])) local_repos_path = os.path.abspath(args[1]) print('project_dir:',project_directory) youngest_revision = int(args[2]) if status_file == "" : usage_and_exit("No status file specified") def main(): global host global user global password global port global repo_path global local_repos_path global status_file global project_directory global remote_base_directory global youngest_revision read_args() #repository,fs_ptr #get youngest revision print("local_repos_path: " + local_repos_path) print('getting youngest revision...') #youngest_revision = fs.youngest_rev(fs_ptr) assert youngest_revision, "Unable to lookup youngest revision." last_sent_revision = get_last_revision() if youngest_revision == last_sent_revision: # no need to continue. we should be up to date. print('done, up-to-date') return if last_sent_revision or youngest_revision < 10: # Only compare revisions if the DAT file contains a valid # revision number. Otherwise we risk waiting forever while # we parse and uploading every revision in the repo in the case # where a repository is retroactively configured to sync with ftp. pysvn_client = pysvn.Client() pysvn_client.callback_get_login = get_login rev1 = pysvn.Revision(pysvn.opt_revision_kind.number, last_sent_revision) rev2 = pysvn.Revision(pysvn.opt_revision_kind.number, youngest_revision) summary = pysvn_client.diff_summarize(repo_path, rev1, repo_path, rev2, True, False) print('summary len:',len(summary)) if len(summary) > 0 : print('connecting to %s...' % host) ftp = FTPClient(host, user, password) print('connected to %s' % host) ftp.base_path = remote_base_directory print('set remote base directory to %s' % remote_base_directory) #iterate through all the differences between revisions for change in summary : #determine whether the path of the change is relevant to the path that is being sent, and modify the path as appropriate. print('change path:',change.path) ftp_relative_path = apply_basedir(change.path) print('ftp rel path:',ftp_relative_path) #only try to sync path if the path is in our project_directory if ftp_relative_path != "" : is_file = (change.node_kind == pysvn.node_kind.file) if str(change.summarize_kind) == "delete" : print("deleting: " + ftp_relative_path) try: ftp.delete_path("/" + ftp_relative_path, is_file) except ftplib.error_perm as e: if 'cannot find the' in str(e) or 'not found' in str(e): # Log, but otherwise ignore path-not-found errors # when deleting, since it's not a disaster if the file # we want to delete is already gone. logging.error(captureErrorMessage(e)) else: raise elif str(change.summarize_kind) == "added" or str(change.summarize_kind) == "modified" : local_file = "" if is_file : local_file = svn_export_temp(pysvn_client, repo_path, rev2, change.path) print("uploading file: " + ftp_relative_path) ftp.upload_path("/" + ftp_relative_path, is_file, local_file) if is_file : os.remove(local_file) elif str(change.summarize_kind) == "normal" : print("skipping 'normal' element: " + ftp_relative_path) else : raise str("Unknown change summarize kind: " + str(change.summarize_kind) + ", path: " + ftp_relative_path) ftp.close() #write back the last revision that was synced print("writing last revision: " + str(youngest_revision)) set_last_revision(youngest_revision) # todo: undo def get_login(a,b,c,d): #arguments don't matter, we're always going to return the same thing try: return True, "svnUsername", "svnPassword", True except Exception as e: logging.error(e) #capture the location of the error frame = inspect.currentframe() stack_trace = traceback.format_stack(frame) logging.debug(stack_trace) #end capture sys.exit(1) #functions for persisting the last successfully synced revision def get_last_revision(): if os.path.isfile(status_file) : f=open(status_file, 'r') line = f.readline() f.close() try: i = int(line) except ValueError: i = 0 else: i = 0 f = open(status_file, 'w') f.write(str(i)) f.close() return i def set_last_revision(rev) : f = open(status_file, 'w') f.write(str(rev)) f.close() #augmented ftp client class that can work off a base directory class FTPClient(ftplib.FTP) : def __init__(self, host, username, password) : self.base_path = "" self.current_path = "" ftplib.FTP.__init__(self, host, username, password) def cwd(self, path) : debug_path = path if self.current_path == "" : self.current_path = self.pwd() print("pwd: " + self.current_path) if not os.path.isabs(path) : debug_path = self.base_path + "<" + path path = os.path.join(self.current_path, path) elif self.base_path != "" : debug_path = self.base_path + ">" + path.lstrip("/") path = os.path.join(self.base_path, path.lstrip("/")) path = os.path.normpath(path) #by this point the path should be absolute. if path != self.current_path : print("change from " + self.current_path + " to " + debug_path) ftplib.FTP.cwd(self, path) self.current_path = path else : print("staying put : " + self.current_path) def cd_or_create(self, path) : assert os.path.isabs(path), "absolute path expected (" + path + ")" try: self.cwd(path) except ftplib.error_perm as e: for folder in path.split('/'): if folder == "" : self.cwd("/") continue try: self.cwd(folder) except: print("mkd: (" + path + "):" + folder) self.mkd(folder) self.cwd(folder) def upload_path(self, path, is_file, local_path) : if is_file: (path, filename) = os.path.split(path) self.cd_or_create(path) # Use read-binary to avoid universal newline support from stripping CR characters. f = open(local_path, 'rb') self.storbinary("STOR " + filename, f) f.close() else: self.cd_or_create(path) def delete_path(self, path, is_file) : (path, filename) = os.path.split(path) print("trying to delete: " + path + ", " + filename) self.cwd(path) try: if is_file : self.delete(filename) else: self.delete_path_recursive(filename) except ftplib.error_perm as e: if 'The system cannot find the' in str(e) or '550 File not found' in str(e): # Log, but otherwise ignore path-not-found errors # when deleting, since it's not a disaster if the file # we want to delete is already gone. logging.error(captureErrorMessage(e)) else: raise def delete_path_recursive(self, path): if path == "/" : raise "WARNING: trying to delete '/'!" for node in self.nlst(path) : if node == path : #it's a file. delete and return self.delete(path) return if node != "." and node != ".." : self.delete_path_recursive(os.path.join(path, node)) try: self.rmd(path) except ftplib.error_perm as msg : sys.stderr.write("Error deleting directory " + os.path.join(self.current_path, path) + " : " + str(msg)) # apply the project_directory setting def apply_basedir(path) : #remove any leading stuff (in this case, "trunk/") and decide whether file should be propagated if not path.startswith(project_directory) : return "" return path.replace(project_directory, "", 1) def svn_export_temp(pysvn_client, base_path, rev, path) : # Causes access denied error. Couldn't deduce Windows-perm issue. # It's possible Python isn't garbage-collecting the open file-handle in time for pysvn to re-open it. # Regardless, just generating a simple filename seems to work. #(fd, dest_path) = tempfile.mkstemp() dest_path = tmpName = '%s.tmp' % __file__ exportPath = os.path.join(base_path, path).replace('\\','/') print('exporting %s to %s' % (exportPath, dest_path)) pysvn_client.export( exportPath, dest_path, force=False, revision=rev, native_eol=None, ignore_externals=False, recurse=True, peg_revision=rev ) return dest_path if __name__ == "__main__": logging.info('svnftp.start') try: main() logging.info('svnftp.done') except Exception as e: # capture the location of the error for debug purposes frame = inspect.currentframe() stack_trace = traceback.format_stack(frame) logging.debug(stack_trace[:-1]) print(stack_trace) # end capture error_text = '\nFATAL EXCEPTION!!!\n'+captureErrorMessage(e) subject = "ALERT: SVN2FTP Error" message = """An Error occurred while trying to FTP an SVN commit. repo_path = %(repo_path)s\n local_repos_path = %(local_repos_path)s\n project_directory = %(project_directory)s\n remote_base_directory = %(remote_base_directory)s\n error_text = %(error_text)s """ % globals() email(toAddrs, message, subject) logging.error(e) Notes/Disclaimers: I have basically no python training so I'm learning as I go and spending lots of time reading docs to figure stuff out. The body of get_login is in a try block because I was getting strange errors saying there was an unhandled exception in callback_get_login. Never figured out why, but it seems fine now. Let sleeping dogs lie, right? The username and password for get_login are currently hard-coded (but correct) just to eliminate variables and try to change as little as possible at once. (I added the svnuser and svnpass arguments to the existing argument parsing.) So that's where I am. I can't figure out why on earth it's not printing anything into svn2ftp.out.log. If you're wondering, the output for one of these failed attempts in svn2ftp.debug.log is: 2012-09-06 15:18:12,496 INFO svnftp.start 2012-09-06 15:18:12,496 INFO svnftp.done And it's no different on a successful run. So there's nothing useful being logged. I'm lost. I've gone way down the rabbit hole on this one, and don't know where to go from here. Any ideas?

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  • Multithreading recommendation based on program description

    - by user260197
    I would like to describe some specifics of my program and get feedback on what the best multithreading model to use would be most applicable. I've spent a lot of time now reading on ThreadPool, Threads, Producer/Consumer, etc. and have yet to come to solid conclusions. I have a list of files (all the same format) but with different contents. I have to perform work on each file. The work consists of reading the file, some processing that takes about 1-2 minutes of straight number crunching, and then writing large output files at the end. I would like the UI interface to still be responsive after I initiate the work on the specified files. Some questions: What model/mechanisms should I use? Producer/Consumer, WorkPool, etc. Should I use a BackgroundWorker in the UI for responsiveness or can I launch the threading from within the Form as long as I leave the UI thread alone to continue responding to user input? How could I take results or status of each individual work on each file and report it to the UI in a thread safe way to give user feedback as the work progresses (there can be close to 1000 files to process) Update: Great feedback so far, very helpful. I'm adding some more details that are asked below: Output is to multiple independent files. One set of output files per "work item" that then themselves gets read and processed by another process before the "work item" is complete The work items/threads do not share any resources. The work items are processed in part using a unmanaged static library that makes use of boost libraries.

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  • multithreading in c#

    - by Lalit Dhake
    Hi, I have console application. In that i have some process that fetch the data from database through different layers ( business and Data access). stores the fetched data in respective objects. Like if data is fetched for student then this data will store (assigned ) to Student object. same for school. and them a delegate call the certain method that generates outputs as per requirement. This process will execute many times say 10 times. Ok? I want to run simultaneously this process. not one will start, it will finish and then second will start. I want after starting 1'st process, just 2'nd , 3rd....10'th must be start. Means it should be multithreading. how can i achieve this ? is that will give me error while connection with data base open and close ? I have tried this concept . but when thread 1'st is starting then data will fetched for thread 1 will stored in its respective (student , school) objects. ok? when simultaneous 2'nd thread starts , but the data is changing of 1'st object ,while control flowing in program. What have to do?

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  • Strange problem with simple multithreading program in Java

    - by Elizabeth
    Hello, I am just starting play with multithreading programming. I would like to my program show alternately character '-' and '+' but it doesn't. My task is to use synchronized keyword. As far I have: class FunnyStringGenerator{ private char c; public FunnyStringGenerator(){ c = '-'; } public synchronized char next(){ if(c == '-'){ c = '+'; } else{ c = '-'; } return c; } } class ThreadToGenerateStr implements Runnable{ FunnyStringGenerator gen; public ThreadToGenerateStr(FunnyStringGenerator fsg){ gen = fsg; } @Override public void run() { for(int i = 0; i < 10; i++){ System.out.print(gen.next()); } } } public class Main{ public static void main(String[] args) throws IOException { FunnyStringGenerator FSG = new FunnyStringGenerator(); ExecutorService exec = Executors.newCachedThreadPool(); for(int i = 0; i < 20; i++){ exec.execute(new ThreadToGenerateStr(FSG)); } } } EDIT: I also testing Thread.sleep in run method instead for loop.

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  • Closest to “Mathematica Graphics[]" drawing environment for Python

    - by 500
    Being only familiar with Mathematica and its Graphics, I have now to learn to draw Graphics using Python for a server. Mostly conditional combination of simple shape. What would be a package for Python that make drawing Graphics as close as possible as the Mathematica Graphics environment ? For Example, I would need to do such thing as in : http://mathematica.stackexchange.com/questions/1010/2d-gaussian-distribution-of-squares-coordinates#comment2475_1010

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  • Python Forgiveness vs. Permission and Duck Typing

    - by darkfeline
    In Python, I often hear that it is better to "beg forgiveness" (exception catching) instead of "ask permission" (type/condition checking). In regards to enforcing duck typing in Python, is this try: x = foo.bar except AttributeError: pass else: do(x) better or worse than if hasattr(foo, "bar"): do(foo.bar) else: pass in terms of performance, readability, "pythonic", or some other important factor?

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  • What does your Python development workbench look like?

    - by Fabian Fagerholm
    First, a scene-setter to this question: Several questions on this site have to do with selection and comparison of Python IDEs. (The top one currently is What IDE to use for Python). In the answers you can see that many Python programmers use simple text editors, many use sophisticated text editors, and many use a variety of what I would call "actual" integrated development environments – a single program in which all development is done: managing project files, interfacing with a version control system, writing code, refactoring code, making build configurations, writing and executing tests, "drawing" GUIs, and so on. Through its GUI, an IDE supports different kinds of workflows to accomplish different tasks during the journey of writing a program or making changes to an existing one. The exact features vary, but a good IDE has sensible workflows and automates things to let the programmer concentrate on the creative parts of writing software. The non-IDE way of writing large programs relies on a collection of tools that are typically single-purpose; they do "one thing well" as per the Unix philosophy. This "non-integrated development environment" can be thought of as a workbench, supported by the OS and generic interaction through a text or graphical shell. The programmer creates workflows in their mind (or in a wiki?), automates parts and builds a personal workbench, often gradually and as experience accumulates. The learning curve is often steeper than with an IDE, but those who have taken the time to do this can often claim deeper understanding of their tools. (Whether they are better programmers is not part of this question.) With advanced editor-platforms like Emacs, the pieces can be integrated into a whole, while with simpler editors like gedit or TextMate, the shell/terminal is typically the "command center" to drive the workbench. Sometimes people extend an existing IDE to suit their needs. What does your Python development workbench look like? What workflows have you developed and how do they work? For the first question, please give the main "driving" program – the one that you use to control the rest (Emacs, shell, etc.) the "small tools" -- the programs you reach for when doing different tasks For the second question, please describe what the goal of the workflow is (eg. "set up a new project" or "doing initial code design" or "adding a feature" or "executing tests") what steps are in the workflow and what commands you run for each step (eg. in the shell or in Emacs) Also, please describe the context of your work: do you write small one-off scripts, do you do web development (with what framework?), do you write data-munching applications (what kind of data and for what purpose), do you do scientific computing, desktop apps, or something else? Note: A good answer addresses the perspectives above – it doesn't just list a bunch of tools. It will typically be a long answer, not a short one, and will take some thinking to produce; maybe even observing yourself working.

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  • Bullet physics in python and pygame

    - by Pomg
    I am programming a 2D sidescroller in python and pygame and am having trouble making a bullet go farther than just farther than the player. The bullet travels straight to the ground after i fire it. How, in python code using pygame do I make the bullet go farther. If you need code, here is the method that handles the bullet firing: self.xv += math.sin(math.radians(self.angle)) * self.attrs['speed'] self.yv += math.cos(math.radians(self.angle)) * self.attrs['speed'] self.rect.left += self.xv self.rect.top += self.yv

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  • How to run python script at login screen?

    - by virpara
    I use a python script to set brightness to zero. #!/usr/bin/python import dbus bus = dbus.SessionBus() proxy = bus.get_object('org.gnome.SettingsDaemon', '/org/gnome/SettingsDaemon/Power') iface = dbus.Interface(proxy,dbus_interface='org.gnome.SettingsDaemon.Power.Screen') iface.SetPercentage(0) I've put it in Startup Applications. It works only when I login. There is full brightness at login screen. Where should I put this so that it sets brightness to zero at login screen?

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  • Why do iterators in Python raise an exception?

    - by NullUserException
    Here's the syntax for iterators in Java (somewhat similar syntax in C#): Iterator it = sequence.iterator(); while (it.hasNext()) { System.out.println(it.next()); } Which makes sense. Here's the equivalent syntax in Python: it = iter(sequence) while True: try: value = it.next() except StopIteration: break print(value) I thought Exceptions were supposed to be used only in, well, exceptional circumstances. Why does Python use exceptions to stop iteration?

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  • How do i tell ubuntu to only install is asked for and do not bring other dependencies which will break the whole system?

    - by YumYumYum
    How can i only install python-webkit but not other packages? which is showing to install? (no gstreamer*.*, i do not want to have any single files installed in my distro because of GPL license and it slows my machine a lot) $ sudo apt-get install libwebkitgtk-1.0-0 python-webkit Reading package lists... Done Building dependency tree Reading state information... Done The following extra packages will be installed: libgstreamer-plugins-base0.10-0 libgstreamer0.10-0 Suggested packages: gstreamer-codec-install gnome-codec-install gstreamer0.10-tools gstreamer0.10-plugins-base The following NEW packages will be installed: libgstreamer-plugins-base0.10-0 libgstreamer0.10-0 libwebkitgtk-1.0-0 0 upgraded, 3 newly installed, 0 to remove and 333 not upgraded. Need to get 8,231 kB of archives. After this operation, 28.2 MB of additional disk space will be used. Do you want to continue [Y/n]? n Abort.

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  • Why C++ people loves multithreading when it comes to performances?

    - by user1849534
    I have a question, it's about why programmers seems to love concurrency and multi-threaded programs in general. I'm considering 2 main approach here: an async approach basically based on signals, or just an async approach as called by many papers and languages like the new C# 5.0 for example, and a "companion thread" that maanges the policy of your pipeline a concurrent approach or multi-threading approach I will just say that I'm thinking about the hardware here and the worst case scenario, and I have tested this 2 paradigms myself, the async paradigm is a winner at the point that I don't get why people 90% of the time talk about concurrency when they wont to speed up things or make a good use of their resources. I have tested multi-threaded programs and async program on an old machine with an Intel quad-core that doesn't offer a memory controller inside the CPU, the memory is managed entirely by the motherboard, well in this case performances are horrible with a multi-threaded application, even a relatively low number of threads like 3-4-5 can be a problem, the application is unresponsive and is just slow and unpleasant. A good async approach is, on the other hand, probably not faster but it's not worst either, my application just waits for the result and doesn't hangs, it's responsive and there is a much better scaling going on. I have also discovered that a context change in the threading world it's not that cheap in real world scenario, it's infact quite expensive especially when you have more than 2 threads that need to cycle and swap among each other to be computed. On modern CPUs the situation it's not really that different, the memory controller it's integrated but my point is that an x86 CPUs is basically a serial machine and the memory controller works the same way as with the old machine with an external memory controller on the motherboard. The context switch is still a relevant cost in my application and the fact that the memory controller it's integrated or that the newer CPU have more than 2 core it's not bargain for me. For what i have experienced the concurrent approach is good in theory but not that good in practice, with the memory model imposed by the hardware, it's hard to make a good use of this paradigm, also it introduces a lot of issues ranging from the use of my data structures to the join of multiple threads. Also both paradigms do not offer any security abut when the task or the job will be done in a certain point in time, making them really similar from a functional point of view. According to the X86 memory model, why the majority of people suggest to use concurrency with C++ and not just an async aproach ? Also why not considering the worst case scenario of a computer where the context switch is probably more expensive than the computation itself ?

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  • Should I amortize scripting cost via bytecode analysis or multithreading?

    - by user18983
    I'm working on a game sort of thing where users can write arbitrary code for individual agents, and I'm trying to decide the best way to divide up computation time. The simplest option would be to give each agent a set amount of time and skip their turn if it elapses without an action being decided upon, but I would like people to be able to write their agents decision functions without having to think too much about how long its taking unless they really want to. The two approaches I'm considering are giving each agent a set number of bytecode instructions (taking cost into account) each timestep, and making players deal with the consequences of the game state changing between blocks of computation (as with Battlecode) or giving each agent it's own thread and giving each thread equal time on the processor. I'm about equally knowledgeable on both concurrency and bytecode stuff, which is to say not very, so I'm wondering which approach would be best. I have a clearer idea of how I'd structure things if I used bytecode, but less certainty about how to actually implement the analysis. I'm pretty sure I can work up a concurrency based system without much trouble, but I worry it will be messier with more overhead and will add unnecessary complexity to the project.

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  • "Bootstrap" python script in the Windows shell without .py / .pyw associations

    - by PabloG
    Sometimes (in customer's PCs) I need a python script to execute in the Windows shell like a .CMD or .BAT, but without having the .py or .pyw extensions associated with PYTHON / PYTHONW. I came out with a pair of 'quick'n dirty' solutions: 1) """ e:\devtool\python\python.exe %0 :: or %PYTHONPATH%\python.exe goto eof: """ # Python test print "[works, but shows shell errors]" 2) @echo off for /f "skip=4 delims=xxx" %%l in (%0) do @echo %%l | e:\devtools\python\python.exe goto :eof ::---------- # Python test print "[works better, but is somewhat messy]" Do you know a better solution? (ie: more concise or elegant)

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  • Returning a tuple of multipe objects in Python C API

    - by celil
    I am writing a native function that will return multiple Python objects PyObject *V = PyList_New(0); PyObject *E = PyList_New(0); PyObject *F = PyList_New(0); return Py_BuildValue("ooo", V, E, F); This compiles fine, however, when I call it from a Python program, I get an error: SystemError: bad format char passed to Py_BuildValue How can this be done correctly? EDIT: The following works PyObject *rslt = PyTuple_New(3); PyTuple_SetItem(rslt, 0, V); PyTuple_SetItem(rslt, 1, E); PyTuple_SetItem(rslt, 2, F); return rslt; However, isn't there a shorter way to do this?

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  • Python - Check if numbers in list are factors of a number

    - by Zach
    Hey, I have a list of numbers (integers) (say, from 1 to 10). They're not necessarily consecutive, but they are in ascending order. I've prompted the user multiple times to enter a choice of the available numbers. When that number is entered, it is removed from the list along with any of its factors that may be there. I've prevented the user from selecting prime numbers. However, at some point in time, there may be non-prime numbers there, which have no factors remaining. I'm relatively new to Python, so I'm having trouble implementing: Checking if the number selected has no factors remaining (even if it is not prime). Checking if only prime numbers remain, or numbers without factors. I'm thinking of using for statements, but I'm not sure exactly how to implement them. Can anyone offer advice, or code? Thanks in advance... PS. In case anyone's wondering, I'm doing an implementation of the game of Taxman in Python.

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  • Browser Detection Python / mod_python?

    - by cka
    I want to keep some statistics about users and locations in a database. For instance, I would like to store "Mozilla","Firefox","Safari","Chrome","IE", etc... as well as the versions, and possibly the operating system. What I am trying to locate from Python is this string; Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.14) Gecko/2009090216 Ubuntu/9.04 (jaunty) Firefox/3.0.14 Is there an efficient way to use Python or mod_python to detect the http user agent/browser?

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  • Distribute pre-compiled python extension module with distutils

    - by Toji
    Quick one today: I'm learning the in's and out's of Pythons distutils library, and I would like to include a python extension module (.pyd) with my package. I know of course that the recommended way is to have distutils compile the extension at the time the package is created, but this is a fairly complex extension spanning many source files and referencing several external libs so it's going to take some significant playing to get everything working right. In the meantime I have a known working build of the extension coming out of Visual Studio, and would like to use it in the installer as a temporary solution to allow me to focus on other issues. I can't specify it as a module, however, since those apparently must have an explicit .py extension. How could I indicate in my setup.py that I want to include a pre-compiled extension module? (Python 3.1, if it matters)

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  • Error installing gst-python through Homebrew

    - by hrr
    I'm trying to install gst-python and it errors with: brew install gst-python Warning: Your Xcode (4.2.1) is outdated Please install Xcode 4.5.2. ==> Downloading http://gstreamer.freedesktop.org/src/gst-python/gst-python-0.10. Already downloaded: /Library/Caches/Homebrew/gst-python-0.10.22.tar.bz2 ==> ./configure --prefix=/usr/local/Cellar/gst-python/0.10.22 configure: set WARNING_CFLAGS to -Wall -Wdeclaration-after-statement -Wpointer-arith configure: set ERROR_CFLAGS to checking for valgrind... no checking for libraries required to embed python... no configure: error: could not find Python lib This is all after I removed the default OSX python and re-installed it with Homebrew, I've edited /etc/paths and python is working well. I just can't install the package above (gst, pygtk is successfully installed). i was told that I need to install python-devel but I have no idea where from. I'm using OSX Lion 10.7.5 With Python 2.7.3

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  • Installing Mapnik 2.2.0 in windows 7 with Python 2.7

    - by Joan Natalie
    I've been trying to install mapnik on my computer for hours but what i always get when I import mapnik is ImportError: DLL load failed: The specified procedure could not be found. I'm using Windows 7. The currently installed software is Geoserver from Opengeo suite. Here is my path %SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;%SYSTEMROOT%\System32\WindowsPowerShell\v1.0\;C:\Program Files\WIDCOMM\Bluetooth Software\;C:\Program Files\Java\jre7\bin;C:\Program Files\Java\jdk1.7.0_45\bin;C:\Python27;C:\mapnik-v2.2.0\lib My python path: C:\Python27;C:\Python27\Lib;C:\Python27\DLLs;C:\Python27\Lib\lib-tk;C:\Program Files\ArcGIS\bin;C:\\mapnik-v2.2.0\python\2.7\site-packages\;C:\mapnik-v2.2.0\bin\;

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  • How to convert a python utc datetime to a local datetime using only python standard library?

    - by Nitro Zark
    I have a python datetime instance that was created using datetime.utcnow() and persisted in database. For display, I would like to convert the datetime instance reloaded from database to local datetime using the default local timezone (e.g. as if the datetime was create using datetime.now()) How can I convert the utc datetime to a local datetime using only python standard library (e.g. no pytz dependency)? It seems one solution would be to use datetime.astimezone( tz ), but how would do you get the default local timezone?

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