python

time series in python up to microseconds

Hi All I would like to handle time series in python. I have been suggested to use scikit.timeseries but I need to handle up to microseconds and this last, as far as I know, handles up to milliseconds. Do you know any other library able to do that? At some point I need to merge 2 time series sampled at different time, and I would like...

Implementing PyMyType_Check methods with Python C API?

All the Python-provided types have a check method (i.e., PyList_Check) that allows you to check if an arbitrary PyObject* is actually a specific type. How can I implement this for my own types? I haven't found anything good online for this, though it seems like a pretty normal thing to want to do. Also, maybe I'm just terrible at look...

Asynchronous daemon processing / ORM interaction with Django

I'm looking for a way to do asynchronous data processing with a daemon that uses Django ORM. However, the ORM isn't thread-safe; it's not thread-safe to try to retrieve / modify django objects from within threads. So I'm wondering what the correct way to achieve asynchrony is? Basically what I need to accomplish is taking a list of use...

How can I specify a relative path in a Python logging config file?

I've the following file to config logging: [loggers] keys=root [handlers] keys = root [formatters] keys = generic # Loggers [logger_root] level = DEBUG handlers = root # Handlers [handler_root] class = handlers.RotatingFileHandler args = ("test.log", "maxBytes=1*1024*1024", "backupCount=10") level = NOTSET formatter = generic # For...

too many threads due to synch communication

I'm using threads and xmlrpclib in python at the same time. Periodically, I create a bunch of thread to complete a service on a remote server via xmlrpclib. The problem is that, there are times that the remote server doesn't answer. This causes the thread to wait forever for a response which it never gets. Over time, number of threads in...

Regular expression works normally, but fails when placed in an XML schema

I have a simple doc.xml file which contains a single root element with a Timestamp attribute: <?xml version="1.0" encoding="utf-8"?> <root Timestamp="04-21-2010 16:00:19.000" /> I'd like to validate this document against a my simple schema.xsd to make sure that the Timestamp is in the correct format: <?xml version="1.0" encoding="utf...

Python byte per byte XOR decryption

I have an XOR encypted file by a VB.net program using this function to scramble: Public Class Crypter ... 'This Will convert String to bytes, then call the other function. Public Function Crypt(ByVal Data As String) As String Return Encoding.Default.GetString(Crypt(Encoding.Default.GetBytes(Data))) End Function ...

How to bind a double precision using psycopg2

I'm trying to bind a float to a postgresql double precision using psycopg2. ele = 1.0/3.0 dic = {'name': 'test', 'ele': ele} sql = '''insert into waypoints (name, elevation) values (%(name)s, %(ele)s)''' cur = db.cursor() cur.execute(sql, dic) db.commit() sql = """select elevation from waypoints where name = 'test'""" cur.execute(sql_...

How do you leave comments/like a specific page of a Facebook Canvas app?

I'm building a tabbed Facebook Canvas app that requires individual images to be "Like"d and commented on. Since each image is loaded up as its own page, in this style: http://apps.facebook.com/appname/image/333/ (which translates to: www.mydomain.com/image/333/) I was hoping I could just get a UID for each "image" page and then comment...

Shared mmap co-ordination using fcntl locks?

When using mmap() for shared memory (from Linux, or other UNIX-like systems) is it possible (and portable) to use fcntl() (or flock() or lockf() functions) to co-ordinate access to the mapping? Responses to this SO question seems to suggest that it should work. The idea I have in mind would be to have the shared memory structured with...

What's the best way to aggregate the boolean values of a Python dictionary?

For the following Python dictionary: dict = { 'stackoverflow': True, 'superuser': False, 'serverfault': False, 'meta': True, } I want to aggregate the boolean values above into the following boolean expression: dict['stackoverflow'] and dict['superuser'] and dict['serverfault'] and dict['meta'] The above should retu...

Loading datasets from datastore and merge into single dictionary. Resource problem.

Hi, I have a productdatabase that contains products, parts and labels for each part based on langcodes. The problem I'm having and haven't got around is a huge amount of resource used to get the different datasets and merging them into a dict to suit my needs. The products in the database are based on a number of parts that is of a c...

Huge Graph Structure

I'm developing an application in which I need a structure to represent a huge graph (between 1000000 and 6000000 nodes and 100 or 600 edges) in memory. The edges representation will contain some attributes of the relation. I have tried a memory map representation, arrays, dictionaries and strings to represent that structure in memory, ...

How do I require that an element has either one set of attributes or another in an XSD schema?

I'm working with an XML document where a tag must either have one set of attributes or another. For example, it needs to either look like <tag foo="hello" bar="kitty" /> or <tag spam="goodbye" eggs="world" /> e.g. <root> <tag foo="hello" bar="kitty" /> <tag spam="goodbye" eggs="world" /> </root> So I have an XSD schema where ...

What is the best practices for checking if the user of a Python script has root-like privileges?

I have a Python script that will be doing a lot of things that would require root-level privileges, such as moving files in /etc, installing with apt-get, and so on. I currently have: if os.geteuid() != 0: exit("You need to have root privileges to run this script.\nPlease try again, this time using 'sudo'. Exiting.") Is this the b...

How to get a html elements with python lxml

Hello! I have this html code: <table> <tr> <td class="test"><b><a href="">aaa</a></b></td> <td class="test">bbb</td> <td class="test">ccc</td> <td class="test"><small>ddd</small></td> </tr> <tr> <td class="test"><b><a href="">eee</a></b></td> <td class="test">fff</td> <td class="test">ggg</td> <td class="test"><small...

how do I obtain all the elements of a generator expression I wrote?

I am using google-app-engine webapp, part of the code is : class Post(db.Model): title = db.StringProperty(required=True) def categories(self): return (x.category for x in self.postcategory_set) class Category(db.Model): name = db.StringProperty() class PostCategory(db.Model): post = db.ReferenceProperty(Post)...

super function doesn't work inside a maya python module

Somehow, this works fine in the Maya/Python script editor, but fails when it's inside of my module code. Anyone have any ideas? class ControlShape(object): def __init__(self, *args, **kwargs): print 'Inside ControlShape...' class Cross(ControlShape): def __init__(self, *args, **kwargs): print 'Entering Cross...'...

UDP security and identifying incoming data.

I have been creating an application using UDP for transmitting and receiving information. The problem I am running into is security. Right now I am using the IP/socketid in determining what data belongs to whom. However, I have been reading about how people could simply spoof their IP, then just send data as a specific IP. So this seems...

Efficient way to combine results of two database queries.

I have two tables on different servers, and I'd like some help finding an efficient way to combine and match the datasets. Here's an example: From server 1, which holds our stories, I perform a query like: query = """SELECT author_id, title, text FROM stories ORDER BY timestamp_created DESC LIMIT 10 ...