python - Threading in a django app -

-

i'm trying create call scrobbler. task read delicious user queue, fetch of bookmarks , put them in bookmarks queue. should go through queue, parsing , store data in database.

this calls threading because of time spent waiting delicious respond , bookmarked websites respond , passed through api's , silly wait that.

however having trouble threading , keep getting strange errors database tables not being defined. appreciated :)

here's relevant code:

# relevant model # class bookmark(models.model):  account = models.foreignkey( delicious )  url = models.charfield( max_length=4096 )  tags = models.textfield()  hash = models.charfield( max_length=32 )  meta = models.charfield( max_length=32 )  # bookmark queue reading # def scrobble_bookmark(account):  try:   bookmark = bookmark.objects.all()[0]  except bookmark.doesnotexist:   return false   bookmark.delete()   tags = bookmark.tags.split(' ')  user = bookmark.account.user   concept in concepts.extract( bookmark.url ):   tag in tags:    concepts.relate( user, concept['name'], tag )   return true  def scrobble_bookmarks(account):  semaphore = semaphore(10)  in xrange(bookmark.objects.count()):   thread = bookmark_scrobble(account, semaphore)   thread.start()  class bookmark_scrobble(thread):  def __init__(self, account, semaphore):   thread.__init__(self)   self.account = account   self.semaphore = semaphore   def run(self):   self.semaphore.acquire()   try:    scrobble_bookmark(self.account)   finally:    self.semaphore.release()

this error get:

exception in thread thread-65: traceback (most recent call last):   file "/usr/lib/python2.6/threading.py", line 525, in __bootstrap_inner     self.run()   file     "/home/swizec/documents/trees/bookmarklet_server/../bookmarklet_server/scrobbler/scrobbler.py", line 60, in run     scrobble_bookmark(self.account)   file     "/home/swizec/documents/trees/bookmarklet_server/../bookmarklet_server/scrobbler/scrobbler.py", line 28, in scrobble_bookmark     bookmark = bookmark.objects.all()[0]   file "/usr/local/lib/python2.6/dist-packages/django/db/models/query.py", line 152, in __getitem__     return list(qs)[0]   file "/usr/local/lib/python2.6/dist-packages/django/db/models/query.py", line 76, in __len__ self._result_cache.extend(list(self._iter))   file "/usr/local/lib/python2.6/dist-packages/django/db/models/query.py", line 231, in iterator     row in self.query.results_iter():   file "/usr/local/lib/python2.6/dist-packages/django/db/models/sql/query.py", line 281, in results_iter     rows in self.execute_sql(multi):   file "/usr/local/lib/python2.6/dist-packages/django/db/models/sql/query.py", line 2373, in execute_sql cursor.execute(sql, params)   file "/usr/local/lib/python2.6/dist-packages/django/db/backends/sqlite3/base.py", line 193, in execute     return database.cursor.execute(self, query, params) operationalerror: no such table: scrobbler_bookmark

ps: other tests depending on same table pass flying colours.

you can not use threading in memory databases (sqlite3 in case) in django see bug. might work postgresql or mysql.

i'd recommend celeryd instead of threads, message queues easier work threading.


Comments

Post a Comment

Popular posts from this blog

c++ - Convert big endian to little endian when reading from a binary file -

-
this question has answer here: how convert between big-endian , little-endian values in c++? 28 answers i've been looking around how convert big-endian little-endians. didn't find solve problem. seem there's many way can conversion. anyway following code works ok in big-endian system. how should write conversion function work on little-endian system well? this homework, since systems @ school running big-endian system. it's got curious , wanted make work on home computer also #include <iostream> #include <fstream> using namespace std; int main() { ifstream file; file.open("file.bin", ios::in | ios::binary); if(!file) cerr << "not able read" << endl; else { cout << "opened" << endl; int i_var; double d_var; while(!file.eof()) {...
Read more

C#: Application without a window or taskbar item (background app) that can still use Console.WriteLine() -

-
i'm trying create application adheres following: no taskbar no console or form window can utilize console.writeline() . (i.e. if executes app command prompt write console.) the problem if create windows form (or wpf) application can have there no taskbar, console or window show up, console.writeline() nothing. if create console app, writes console, can't figure out how hide (and if did hide it, write command prompt window?)... how do this? just create standard console application. callers responsibility hide window caused program (from how run c# console application console hidden ): system.diagnostics.processstartinfo start = new system.diagnostics.processstartinfo(); start.filename = dir + @"\myprocesstostart.exe"; start.windowstyle = system.diagnostics.processwindowstyle.hidden;
Read more

unicode - Are email addresses allowed to contain non-alphanumeric characters? -

-
i'm building website using `django. website have significant users non-english speaking countries. i want know if there technical restrictions on types of characters email address contain. are email addresses allowed contain english alphabets, numbers, "_", "@" , "."? are allowed contain non-english alphabets "é" or "ü"? are allowed contain chinese or japanese or other unicode characters? email address consists of 2 parts local before @ , domain goes after. rules these parts different: for local part can use ascii: latin letters - z - z digits 0 - 9 special characters !#$%&'*+-/=?^_`{|}~ dot ., not first or last, , not in sequence space , "(),:;<>@[] characters allowed restrictions (they allowed inside quoted string, backslash or double-quote must preceded backslash) plus since 2012 can use international characters above u+007f , encoded as utf-8 . domain part more res...
Read more