Tuesday 15 October 2013

Pymix fix: short note on compiling PyMix on Ubuntu

A fix for users of Python 2.6 or 2.7 when installing PyMix:

Sunday 13 October 2013

How to pass arguments to python programs ...

... the right way (in my opinion). This is the basic template I always use. Not complicated, but the general formula might be useful to someone.

It allows you to pass arguments to a program with the use of flags, so they can be provided in any order. It has a 'help' flag (-h), will raise an error if no arguments are passed.

In this example one of the inputs (-a) is supposed to be a file. If the file is not provided, it uses Tkinter to open a simple 'get file' window dialog.

It then parses the other arguments out. Here I have assumed one argument is a string, one is a float, and one is an integer. If any arguments are not provided, it creates variables based on default variables. It prints everything it's doing to the screen.


Saturday 12 October 2013

Kivy python script for capturing displaying webcam

Kivy is very cool. It allows you to make graphical user interfaces for computers, tablets and smart phones ... in Python. Which is great for people like me. And you, I'm sure. And it's open source, of course.

Today was my first foray into programming using Kivy. Here was my first 'app'. It's not very sophisticated, but I find Kivy's documentation rather impenetrable and frustratingly lacking in examples. Therefore I hope more people like me post their code and projects on blogs.

Right, it detects and displays your webcam on the screen, draws a little button in the bottom. When you press that button it takes a screengrab and writes it to an image file. Voila! Maximise the window before you take a screen shot for best effects.



Simple Python script to write a list of coordinates to a .geojson file

This has probably been done better elsewhere, but here's a really simple way to write a geojson file programmatically to display a set of coordinates, without having to bother learning the syntax of yet another python library. Geojson is a cool little format, open source and really easy.

Below, arrays x and y are decimal longitude and latitude respectively. The code would have to be modified to include a description for each coordinate, which could be included easily on line 15 if in the form of an iterable list.