Popular recipes tagged "programming"

Implementing class-based callbacks in Python (Python)

2017-04-20T23:34:50-07:00

Python recipe 580788 by Vasudev Ram (callbacks, classes, functions, methods, objects, programming, python).

This is a follow-on to this recently posted recipe:

Implementing function-based callbacks in Python: https://code.activestate.com/recipes/580787-implementing-function-based-callbacks-in-python/?in=user-4173351

This new recipe shows how to create and use callbacks in Python, using classes with methods, instead of plain functions, as was done in the recipe linked above. All other points such as reasons and benefits for using callbacks, are more or less the same as mentioned in the previous recipe, except that class instances can carry state around, so to that extent, the two approaches are different.

https://jugad2.blogspot.in/2017/04/python-callbacks-using-classes-and.html

Simulating an unless (reverse if) statement in Python (Python)

2017-02-23T22:38:50-08:00

Python recipe 580758 by Vasudev Ram (features, if, perl, programming, python, trick).

This recipe shows how to simulate an unless statement (a sort of reverse if, like Perl has), in Python. It is just for fun and as an experiment, not meant for real use, because the effect of unless can easily be got by negating the sense of the condition in an if statement.

More details and output here:

https://jugad2.blogspot.in/2017/02/perl-like-unless-reverse-if-feature-in.html

Python one-liner to compare two files (Python)

2016-03-28T21:36:31-07:00

Python recipe 580632 by Vasudev Ram (comparison, file, files, programming, python).

As the title says ...

It prints True if the files compared are the same, and False if they differ (either in size or in content).

Hamming Neighbors (Python)

2013-01-17T20:50:21-08:00

Python recipe 578423 by Yong Shin (distance, dynamic, hamming, programming).

HammingNeighbors returns all integers that are k number of bits away (i.e. k Hamming distance away) from an integer.
The algorithm uses dynamic programming.

Libreenect (OpenKinect) Minimum Value Joystick With Display - Kinect Demo Using OpenKinect SDK (Python)

2012-03-18T18:52:42-07:00

Python recipe 578080 by Alexander James Wallar (3d, computer_vision, depth, joystick, kinect, libfreenect, numpy, opencv, programming, pygame, python, virtual_joystick). Revision 3.

This demo requires you to be using a Linux machine and to have libfreenect installed with the python wrapper. This demo also requires you to have opencv, numpy, and pygame. They can all be installed using sudo apt-get install {PROGRAM NAME HERE}. Here are instructions on installing libfreenect: http://openkinect.org/wiki/Getting_Started. Okay, so what this demo does is finds the minimum point on the depth image and uses the index of this minimum point to create a four button joystick that codes for 'A', 'B', 'X', 'Y'. It also uses the minimum point and the RGB image to put a circle on the minimum point on the screen. So basically a dot will follow your hand on the RGB image. If the minimum value is larger than 600 (arbitrary units), the color of the dot will change from red to purple and the dot will remain stationary. Also, if the Kinect is not properly opened the first time, unplug it and plug it back in and run in the terminal sudo freenect-glview. After try running the program again. One more thing, this code requires super user privileges so run it through the terminal. Here is how to do this for linux n00bs.

Change your directory the the directory the code is in (use cd {PATH})
Run the code using sudo python {FILENAME}
Don't forget to add the the .py at the end