python

Can someone here explain constructors and destructors in python - simple explanation required - new to programming

i will try to see if it makes sense :- class Person: '''Represents a person ''' population = 0 def __init__(self,name): //some statements and population += 1 def __del__(self): //some statements and population -= 1 def sayHi(self): '''grettings from person''' print 'Hi My name i...

Python optimization

Hi, I do like this: f = open('wl4.txt', 'w') hh = 0 ###################################### for n in range(1,5): for l in range(33,127): if n==1: b = chr(l) + '\n' f.write(b) hh += 1 elif n==2: for s0 in range(33, 127): b = chr(l) + chr(s0) + ...

Object for storing strings in Python

class MyWriter: def __init__(self, stdout): self.stdout = stdout self.dumps = [] def write(self, text): self.stdout.write(smart_unicode(text).encode('cp1251')) self.dumps.append(text) def close(self): self.stdout.close() writer = MyWriter(sys.stdout) save = sys.stdout sys.stdout ...

how to read url data

#!/usr/bin/env python # # Copyright 2007 Google Inc. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writ...

[Python] EOL character in Linux and Windows

I'm writing a simple script, that just connects to telnet port, listens everything on it, staying connected and when some string, for example '123' appears, script do something. I use tn.read_until("123", 2), but when '123' appears, script just disconnects. How to make it stay online? ...

vectorize is indeterminate

I'm trying to vectorize a simple function in numpy and getting inconsistent behavior. I expect my code to return 0 for values < 0.5 and the unchanged value otherwise. Strangely, different runs of the script from the command line yield varying results: sometimes it works correctly, and sometimes I get all 0's. It doesn't matter which ...

Python twisted Reactor class

What is the significance of the decorators @reactor.callWhenRunning, @results_deferred.addCallback @results_deferred.addErrback. Also what are deferred strings, for example in the twisted.internet.utils.getProcessOutput() returns a deferred string what exactly is happening here? I am new to twisted hence this might be a very ...

Match multiline regex in file object

How can I extract the groups from this regex from a file object (data.txt)? import numpy as np import re import os ifile = open("data.txt",'r') # Regex pattern pattern = re.compile(r""" ^Time:(\d{2}:\d{2}:\d{2}) # Time: 12:34:56 at beginning of line \r{2} # Two carriage return ...

Python ImportError when executing 'import.py', but not when executing 'python import.py'

I am running Cygwin Python version 2.5.2. I have a three-line source file, called import.py: #!/usr/bin/python import xml.etree.ElementTree as ET print "Success!" When I execute "python import.py", it works: C:\Temp>python import.py Success! When I run the python interpreter and type the commands, it works: C:\Temp>python Python ...

Odd nested dictionary behavior in python

Im new two python and am trying to grow a dictionary of dictionaries. I have done this in php and perl but python is behaving very differently. Im sure it makes sense to those more familiar with python. Here is my code: colnames = ['name','dob','id']; tablehashcopy = {}; tablehashcopy = dict.fromkeys(colnames,{}); tablehashcopy['name']...

What is the difference between trapping and handling an exception?

I'm looking into exception handling in python and a blog post I read differentiated between trapping and handling an exception. Can someone explain the core difference between these two, both in python specifically and the overall conceptual difference? A google search for 'exception trapping handling' isn't super-useful. ...

Removing duplicates (within a given tolerance) from a Numpy array of vectors

I have an Nx5 array containing N vectors of form 'id', 'x', 'y', 'z' and 'energy'. I need to remove duplicate points (i.e. where x, y, z all match) within a tolerance of say 0.1. Ideally I could create a function where I pass in the array, columns that need to match and a tolerance on the match. Following this thread on Scipy-user, I ca...

Python to MATLAB: exporting list of strings using scipy.io

I am trying to export a list of text strings from Python to MATLAB using scipy.io. I would like to use scipy.io because my desired .mat file should include both numerical matrices (which I learned to do here) and text cell arrays. I tried: import scipy.io my_list = ['abc', 'def', 'ghi'] scipy.io.savemat('test.mat', mdict={'my_list': my...

error in fetching url data

from google.appengine.ext import webapp from google.appengine.ext.webapp import util from google.appengine.ext import db from google.appengine.api import urlfetch class TrakHtml(db.Model): hawb = db.StringProperty(required=False) htmlData = db.TextProperty() class MainHandler(webapp.RequestHandler): def get(self): Traks = lis...

How can I set controls for a web page ??

I have this login page with https, and i reach to this approach:: import ClientForm import urllib2 request = urllib2.Request("http://ritaj.birzeit.edu") response = urllib2.urlopen(request) forms = ClientForms.ParseResponseEx(response) response.close() f = forms[0] username = str(raw_input("Username: ")) password = str(raw_input("Passw...

Finding unique maximum values in a list using python

Hi I have a list of points as shown below points=[ [x0,y0,v0], [x1,y1,v1], [x2,y2,v2].......... [xn,yn,vn]] Some of the points have duplicate x,y values. What I want to do is to extract the unique maximum value x,y points For example, if I have points [1,2,5] [1,1,3] [1,2,7] [1,7,3] I would like to obtain the list [1,1,3] [1,2...

What is the best, python or bash for selectively concatenating lots of files?

Hi, I have around 20000 files coming from the output of some program, and their names follow the format: data1.txt data2.txt ... data99.txt data100.txt ... data999.txt data1000.txt ... data20000.txt I would like to write a script that gets as input argument the number N. Then it makes blocks of N concatenated files, so if N=5, it wou...

Last matching symbol in Regex

I couldn't find a more descriptive title, but here there is an example: import re m = re.search(r"\((?P<remixer>.+) (Remix)\)", "Title (Menda Remix)") m.group("remixer") # returns 'Menda' OK m = re.search(r"\((?P<remixer>.+) (Remix)\)", "Title (Blabla) (Menda Remix)") m.group("remixer") # returns 'Blabla) (Menda' FAIL This regex finds...

How i can convert integer in to 'binary' in python

In Ruby i do so asd = 123 asd = '%b' % asd # => "1111011" ...

Python - Why use anything other than uuid4() for unique strings?

I see quit a few implementations of unique string generation for things like uploaded image names, session IDs, et al, and many of them employ the usage of hashes like SHA1, or others. I'm not questioning the legitimacy of using custom methods like this, but rather just the reason. If I want a unique string, I just say this: >>> import...