python

Creating a spider using Scrapy, Spider generation error.

I just downloaded Scrapy (web crawler) on Windows 32 and have just created a new project folder using the "scrapy-ctl.py startproject dmoz" command in dos. I then proceeded to created the first spider using the command: scrapy-ctl.py genspider myspider myspdier-domain.com but it did not work and returns the error: Error running: scrap...

Google app engine: empty property in datastore

Dear All, Let say I have a model: class A(db.Model): B = db.StringProperty() C = db.StringProperty() How do I query if I wanted to search all empty property (not None, just empty) in C using python? ...

What will be the setup process for website development?

Hi, I want to create a simple site for my personal usage. And this only in python based technologies. So I want to get a expert oponian on this topic. What should i used as platform? I did a search for available options and found Django, grok, web2py and many more of these. Which one a novice use should use? If I choose to use only th...

Using netbeans as IDE for Python

I am about to embark on learning Python (largely for the purposes of using it as scripting glue between my applications). I use Netbeans (6.8) on Linux for both my C++ and PHP development work. Ideally, I would like to use the same IDE for Python - and there is a Python plugin for Netbeans (admittedly, its still in Beta). Does anyone h...

Go through a number of functions in Python

I have an unknown number of functions in my python script (well, it is known, but not constant) that start with site_... I was wondering if there's a way to go through all of these functions in some main function that calls for them. something like: foreach function_that_has_site_ as coolfunc if coolfunc(blabla,yada) == true: r...

Django: How do I get logging working?

I've added the following to my settings.py file: import logging ... logging.basicConfig(level=logging.DEBUG, format='%(asctime)s %(levelname)s %(message)s', filename=os.path.join(rootdir, 'django.log'), filemode='a+') And in views.py, I've added: import logging log = logging.getLogger(__name__) ... log.info("testing 123!"...

How Can I Find a List of All Exceptions That a Given Library Function Throws in Python?

Sorry for the long title, but it seems most descriptive for my question. Basically, I'm having a difficult time finding exception information in the official python documentation. For example, in one program I'm currently writing, I'm using the shutil libary's move function: from shutil import move move('somefile.txt', '/tmp/somefile.t...

Python: how to inherite and override

Consider this situation: I get an object of type A which has the function f. I.e: class A: def f(self): print 'in f' def h(self): print 'in h' and I get an instance of this class but I want to override the f function but save the rest of the functionality of A. So what I was thinking was something of the sort: clas...

keep open windows console after a python syntax error

File associations on my machine (winxp home) are such that a python script is directly opened with the python interpreter. If I double click on a python script a console window runs and every thing is fine - as long as there is no syntax error in the script. In that case the console window opens up for a moment but it is closed immediat...

Can this Django query be improved?

Given a model structure like this: class Book(models.Model): user = models.ForeignKey(User) class Readingdate(models.Model): book = models.ForeignKey(Book) date = models.DateField() One book may have several Readingdates. How do I list books having at least one Readingdate within a specific year? I can do this: from_d...

Python Error-Checking Standard Practice

Hi, I have a question regarding error checking in Python. Let's say I have a function that takes a file path as an input: def myFunction(filepath): infile = open(filepath) #etc etc... One possible precondition would be that the file should exist. There are a few possible ways to check for this precondition, and I'm just won...

Ping from AppEngine

I know I can fetch url from AppEngine. But I just want to ping a website, without to get any other data. Is it possible? ...

Feedback on using ASE on Android?

Has anyone made use of ASE (Android scripting enviroment) for anything other than proof of concept apps? What are the major limitations? Any feedback would be great. ...

Java or Python distributed compute job (on a student budget)?

I have a large dataset (c. 40G) that I want to use for some NLP (largely embarrassingly parallel) over a couple of computers in the lab, to which i do not have root access, and only 1G of user space. I experimented with hadoop, but of course this was dead in the water-- the data is stored on an external usb hard drive, and i cant load it...

How to catch an exception thrown in ctypes?

I am working with some C code called from Python using ctypes. Somewhere in the bowels of the C library, an exception is occurring and/or abort() is being called. Is there any way I can catch this in my Python caller code? (Platform is Linux) ...

Modify an XML file in Python

Hi, I have two file. I have to modify the file one in a particular node and add in a list of child. The list is in the file2. Can I do it, and how? from xml.dom.minidom import Document from xml.dom import minidom file1=modificare.xml file2=sorgente.xml xmldoc=minidom.parse(file1) for Node in xmldoc.getElementsByTagName("Sampler"): ...

Inserting rows while fetching(from another table) in SQLite

I'm getting this error no matter what with python and sqlite. File "addbooks.py", line 77, in saveBook conn.commit() sqlite3.OperationalError: cannot commit transaction - SQL statements in progress The code looks like this: conn = sqlite3.connect(fname) cread = conn.cursor() cread.execute('''select book_text from table'''...

Help Me: Loading Qt dialogs from python Scripts

Hello, im a novice into developing an application using backend as Python (2.5) and Qt(3) as front end GUI designer. I have 5 diffrent dialogs to implement the scripts. i just know to load the window (main window) from qt import * from dialogselectkernelfile import * from formcopyextract import * import sys if __nam...

Python: Filter a dictionary

Hi, I have a dictionary of points, say: >>> points={'a':(3,4), 'b':(1,2), 'c':(5,5), 'd':(3,3)} I want to create a new dictionary with all the points whose x and y value is smaller than 5, i.e. points 'a', 'b' and 'd'. According to the the book, each dictionary has the items() function, which returns a list of (key, pair) tuple: >...

Using Python to add/remove Ubuntu login script items

I have written a Python application and would like to give my users the option of having the app automatically launch itself when the user logs in. It is important that the user is able to toggle this option on/off from within the app itself, rather than having to manually edit login scripts, so this needs to be done from within the Pyth...