Latest recipes by Anand

Yet again, one more enum for Python (Python)

2010-02-22T22:53:42-08:00

Python recipe 577063 by Anand (enum).

This is a fork of recipe #577024 which describes an enum type for Python using __slots__ and read-only variables. Apart from the enum with default positional argument values, this one adds another enum type using keyword arguments.

TwitterCmd - Interactive console for twittering (Python)

2009-10-08T02:15:19-07:00

Python recipe 576923 by Anand (command, microblogging, shortcuts, twitter). Revision 4.

TwitterCmd is an interactive console for twitter built on top of python-twitter library. It provides short, easy to remember commands for most twitter actions and provides a one-way interaction with the Python interpreter, exposing its objects to further inspection by the python-twitter API.

Pretty-print XML (Python)

2009-05-13T07:47:45-07:00

Python recipe 576750 by Anand (text, xml).

One-liner to pretty print an XML file using xml.dom.minidom.

Pyscanlogger - Python Port scan detector (Python)

2010-03-17T07:27:15-07:00

Python recipe 576690 by Anand (network, programs, security). Revision 5.

A pure Python program to detect network port scanning attacks. Currently logs different TCP port scans. Can run in the background like a daemon and log attacks to a log file.

Multithreaded FIFO Gate (Python)

2008-09-08T08:29:14-07:00

Python recipe 576418 by Anand (semaphores, synchronization, system, threading). Revision 5.

While programming with multiple threads, sometimes one needs a construct which allows to suspend the execution of a set of running threads. This is normally required by an outside thread which wants to suspend the running threads for performing a specific action. The threads need to resume after the action in the same order in which they got suspended.

A thread gate (or gateway) allows you to do this. It acts like a gate through which only one thread can pass at a time. By default the gate is open, allowing all threads to "enter" the gate. When a thread calls "close", the gate is closed, blocking any threads which make a further call to "enter", till the gate is re-opened by the owner, whence the threads resume the order in which they got blocked.

The real-life parallel for this is a human operated level cross, which allows only one vehicle to pass at a time.

List classes, methods and functions in a module (Python)

2008-10-22T08:15:26-07:00

Python recipe 553262 by Anand (programs). Revision 5.

The recipe provides a method "describe" which takes a module as argument and describes classes, methods and functions in the module. The method/function description provides information on the function/method arguments using the inspect module.

Spin Cursor (Python)

2007-10-31T13:22:40-07:00

Python recipe 534142 by Anand (threads).

A class providing a threaded spin cursor on the console.

Synchronization classes using decorators (Python)

2007-10-08T19:15:42-07:00

Python recipe 533135 by Anand (threads). Revision 2.

This recipe provides decorator classes that can be used to transparently provide synchronization and access control to your resources.

Text to PDF Converter (rewrite) (Python)

2007-09-26T13:32:30-07:00

Python recipe 532908 by Anand (text). Revision 3.

This is a rewrite of my text2pdf converter posted as recipe #189858, which can be used to convert pure text files to PDF.

Chat server & client using select.select (Python)

2007-09-28T08:57:53-07:00

Python recipe 531824 by Anand (network). Revision 3.

This recipe demos how to write a simple command line chat server & client using multiplexing using select.select. The server uses select call to multiplex multiple clients and the client uses it to multiplex command line & socket I/O.

Bitsort algorithm (Python)

2007-09-11T01:47:23-07:00

Python recipe 528942 by Anand (algorithms).

The recipe illustrates a Python implementation of the bitsort algorithm. This algorithm is illustrated in the book "Programming Pearls" by Jon Bentley. The bitsort algorithm provides a very efficient way to sort large numbers in disk files.

Twisted XML RPC server with basic HTTP authentication (Python)

2007-08-09T09:48:48-07:00

Python recipe 526625 by Anand (web). Revision 3.

This recipe illustrates an XML RPC server using twisted with support for HTTP basic client authentication.

Composite design-pattern using dictionaries (Python)

2006-11-07T08:39:25-08:00

Python recipe 498249 by Anand (oop). Revision 2.

The recipe illustrates the composite design pattern by using hierarchical dictionaries. It can be used to process hierarchical, tree-based data structures using Python dictionaries.

Mini-commands using subprocess (Python)

2006-09-26T07:38:58-07:00

Python recipe 498137 by Anand (sysadmin). Revision 2.

A set of template classes which allows to develop custom "mini-command" classes which allow to execute any system command and customize the execution using template strings.

A basic time profiler (Python)

2006-08-03T20:39:37-07:00

Python recipe 496938 by Anand (shortcuts).

This recipe provides a very simple time profiling module which helps you to measure actual execution time for blocks of Python code without peppering your code with many time.time() statements.

Amaze - An object-oriented maze generator/solver in Python (Python)

2006-07-26T15:04:50-07:00

Python recipe 496884 by Anand (algorithms). Revision 10.

This is a simple maze generator & solver written in Python. It is written as a game, consisting of classes which can read mazes from STDIN or a file. It provides a a random maze generator game, which can generate mazes of any dimension and solve it. Use it for fun and learning.

A python replacement for java.util.Properties (Python)

2006-07-28T08:52:19-07:00

Python recipe 496795 by Anand (files). Revision 5.

This recipe provides a quick and easy way to process Java properties files using pure Python. Of course, Jython can always be used, but in situations where Jython cannot be used, this recipe provides a sure-fire drop-in replacement. The Properties class is modelled to duplicate the behaviour of the original as closely as possible.

YARW - Yet Another Registry Wrapper (Python)

2006-04-05T07:13:16-07:00

Python recipe 476229 by Anand (sysadmin). Revision 3.

This recipe provides "Registry", a Windows registry wrapper class that makes it easy to work with the Windows registry. The class works with an inner class named "RegistryKey", which wraps up a Windows registry key and provides methods to access and manipulate the key information. The class provides easy to remember substitutes for long method names of _winreg.

'Zip walker' - Zip file tree generator (Python)

2005-06-16T02:54:02-07:00

Python recipe 425840 by Anand (files).

A generator which provides a quick way to 'walk' a zip file archive. The generator can process multiple zip archives, i.e zip files which contain zip files. Inspired by the os.walk function.

Generic command-line option parser (Python)

2005-06-10T13:46:18-07:00

Python recipe 425345 by Anand (programs). Revision 5.

When writing applications that take command-line arguments in Python, one has to make a choice between the two command-line parsing modules, getopt and optparse. Optparse though more powerful than getopt is available only since Python 2.3. Hence if you are writing a program targeted at Python 2.2 +, you are mostly constrained with using getopt and writing command line parsing code on top of it.

This recipe provides a solution to this problem. It masks the actual module used for option parsing from the application. If optparse is available it is used, otherwise the parser class defaults to getopt. The application only requires to pass a dictionary of option keys and their settings, in a format inspired by optparse, but using tuples.