python

Windows is not passing command line arguments to Python programs executed from the shell.

I'm having trouble getting command line arguments passed to Python programs if I try to execute them directly as executable commands from a Windows command shell. For example, if I have this program (test.py): import sys print "Args: %r" % sys.argv[1:] And execute: >test foo Args: [] as compared to: >python test.py foo Args: ['fo...

Python - multithreading / multiprocessing, very strange problem.

Module run via python myscript.py (not shell input) import uuid import time import multiprocessing def sleep_then_write(content): time.sleep(5) print(content) if __name__ == '__main__': for i in range(15): p = multiprocessing.Process(target=sleep_then_write, args=('Hello World',...

How can I conditionally only log something if it's a certain Class?

Something like this: if self.__class__ == "User": logging.debug("%s non_pks were found" % (str(len(non_pks))) ) In [2]: user = User.objects.get(pk=1) In [3]: user.__class__ Out[3]: <class 'django.contrib.auth.models.User'> In [4]: if user.__class__ == 'django.contrib.auth.models.User': print "yes" ...: In [5]: u...

Need help running Python app as service in Ubuntu with Upstart

I have written a logging application in Python that is meant to start at boot, but I've been unable to start the app with Ubuntu's Upstart init daemon. When run from the terminal with sudo /usr/local/greeenlog/main.pyw, the application works perfectly. Here is what I've tried for the Upstart job: /etc/init/greeenlog.conf # greeenlog ...

Fastest way to find the closest point to a given point in 3D, in Python.

So lets say I have 10,000 points in A and 10,000 points in B and want to find out the closest point in A for every B point. Currently, I simply loop through every point in B and A to find which one is closest in distance. ie. B = [(.5, 1, 1), (1, .1, 1), (1, 1, .2)] A = [(1, 1, .3), (1, 0, 1), (.4, 1, 1)] C = {} for bp in B: closest...

class, dict, self, init, args ?

class attrdict(dict): def __init__(self, *args, **kwargs): dict.__init__(self, *args, **kwargs) self.__dict__ = self a = attrdict(x=1, y=2) print a.x, a.y b = attrdict() b.x, b.y = 1, 2 print b.x, b.y Could somebody explain the first four lines in words? I read about classes and methods. But here it seems very co...

Django Querysets -- need a less expensive way to do this..

Hi all, I have a problem with some code and I believe it is because of the expense of the queryset. I am looking for a much less expensive (in terms of time) way to to this.. log.info("Getting Users") employees = Employee.objects.filter(is_active = True) log.info("Have Users") if opt.supervisor: if opt.hierarchical: peopl...

Building up an array in numpy/scipy by iteration in Python?

Often, I am building an array by iterating through some data, e.g.: my_array = [] for n in range(1000): # do operation, get value my_array.append(value) # cast to array my_array = array(my_array) I find that I have to first build a list and then cast it (using "array") to an array. Is there a way around these? all these casting c...

How to store an arbitrarily long int to a binary file in python?

How can I store and retrieve the number 2**10000 in a binary file in python without converting it to a string? Can it be stored as 10,000 bits? ...

[numpy] storing record arrays in object arrays

I'd like to convert a list of record arrays -- dtype is (uint32, float32) -- into a numpy array of dtype np.object: X = np.array(instances, dtype = np.object) where instances is a list of arrays with data type np.dtype([('f0', '<u4'), ('f1', '<f4')]). However, the above statement results in an array whose elements are also of type n...

Python/X11: find out if user switches virtual desktops

Hello everyone, I'm looking for a way to determine if the user switches virtual desktops under X11. I'm using Python with X11 libraries and PyGTK. I found some working examples in C, but I lack the expertise to translate them into Python, and I read the source code of several X11 pager applications (fbpanel, pypanel), but I can't seem ...

get_or_create generic relations in Django & python debugging in general

I ran the code to create the generically related objects from this demo: http://www.djangoproject.com/documentation/models/generic_relations/ Everything is good intially: >>> bacon.tags.create(tag="fatty") <TaggedItem: fatty> >>> tag, newtag = bacon.tags.get_or_create(tag="fatty") >>> tag <TaggedItem: fatty> >>> newtag False But then...

Using python to write text files with DOS line endings on linux

I want to write text files with DOS/Windows line endings '\r\n' using python running on Linux. It seems to me that there must be a better way than manually putting a '\r\n' at the end of every line or using a line ending conversion utility. Ideally I would like to be able to do something like assign to os.linesep the separator that I wan...

PyQt QAbstractListModel seems to ignore tristate flags

I've been trying for a couple days to figure out why my QAbstractLisModel won't allow a user to toggle a checkable item in three states. The model returns the Qt.IsTristate and Qt.ItemIsUserCheckable in the flags() method, but when the program runs only Qt.Checked and Qt.Unchecked are toggled on edit. class cboxModel(QtCore.QAbstractLis...

Problem building PyGTK on CentOS

I am trying to build PyGTK on CentOS for a non-standard Python (2.6, vs the out-of-the-box 2.4). It requires that I first build pygobject. pygobject-2.18.0 fails at the configure step. The error messages is as follows: checking for GLIB - version >= 2.14.0... no *** Could not run GLIB test program, checking why... *** The test program f...

Does Python doctest remove the need for unit-tests?

Hi all, A fellow developer on a project I am on believes that doctests are as good as unit-tests, and that if a piece of code is doctested, it does not need to be unit-tested. I do not believe this to be the case. Can anyone provide some solid, ideally cited, examples either for or against the argument that doctests replace the need for...

A web framework where AJAX was not an after thought

AJAX is a pain in the ass because it essentially means you'll have to write two sets of similarish code: one for browsers with JavaScript enabled and those without. Not only this, but you have to connect JavaScript events to hook into your models and display the results. And if all that weren't bad enough, you need to send an address c...

Google App Engine: How to disable cache on 'static' files, or make cache smart

I'm using the app engine locally, and sometimes the JS files are being cached between page refreshes, and it drives me crazy because I don't know if there's a bug in the javascript code I'm trying to write, or if the cache is acting up. How do I completely disable cache for *.js files? Or maybe the question is, how to have it be smart,...

Translate Java to Python -- signing strings with PEM certificate files

I'm trying to translate the follow Java into its Python equivalent. // certificate is contents of https://fps.sandbox.amazonaws.com/certs/090909/PKICert.pem // signature is a string that I need to verify. CertificateFactory factory = CertificateFactory.getInstance("X.509"); X509Certificate x509Certificate = (X509Certifi...

Queuing methods to be run on an object by different threads in Python

Let's say I have an object who's class definition looks like: class Command: foo = 5 def run(self, bar): time.sleep(1) self.foo = bar return self.foo If this class is instantiated once, but different threads are hitting its run method (via an HTTP request, handled separately) passing in different args, what is the best...