Psychic Origami

I’ve been writing an application for my other half in recent months to help her organise observations of the children in her class. I’ve actually written two versions of the app. The first was dubbed “Observertron” and in retrospect was overly complex. After a bit of thought I was able to vastly simplify the app, whilst also making it more useful for other purposes beyond making observations.

The app is called NoteComb and is written in Python using wxPython. It’s essentially a specialised text-editor. The core feature is a grep-like search functionality coupled with the ability to edit text in-place during a search. Lines that don’t contain the search terms get hidden, leaving you free to edit the remaining lines as you want:

I’ve decided to take the time and try to package it up “properly”. So NoteComb is available as Mac and Windows apps, complete with icons etc. In fact to “regular” users it should appear that NoteComb is an app like any other – the fact it’s written using Python is largely incidental.

This packaging works pretty well overall and is pretty seamless once the app is downloaded, but it does tend to make for rather large apps. The Windows version when packaged as an installer runs in at about 4Mb, which isn’t too crazy, but the OS X app packed into a compressed DMG file weighs in at 15Mb! At the end of the day the app does include Python + wxPython + various libraries, so it’s not a surprise really, but I guess I was kind of hoping that I might develop in Python and get everything for free…

This is an early version of NoteComb (version 0.2.1), but it’s core functionality is there. Most of the extra work I’ve done has been on adding those little extra bits that aren’t core to the app, but are generally just expected (e.g. remembering previous window positions, copy/paste, undo/redo etc).

So feel free to download NoteComb and give it a go.

I’ve updated the relevant wxPython wiki page with this info, but thought i’d record it here for posterity too.

I’m currently playing around with writing a wxPython app. It’s at the point where I’m starting to package it into executables to be run without needing Python installed.

Py2exe is the tool I’m using for creating a windows app (and py2app for the mac). It’s possible to specify an icon for the executable you create with py2exe. However it’d be nice if this same icon would be used as the icon for frames created by that app. One could include an extra icon as a resource and load that up, but this seems counter to the whole DRY principle. Instead it’d be better to load the same icon from the executable we have created already.

Consulting the wxPython wiki showed that some enterprising souls had already had a go at doing this, but the solutions there relied on the win32api modules amongst others. My Windows machine didn’t have this module installed (as it was running Python 2.5) and looking at the 2nd solution proposed I saw a way to remove this dependency (and thus decrease the size of the final exe as it would not need to include the extra dll’s etc).

So here’s the sample code, from the wiki, I posted:

import wx, sys

class MyFrame(wx.Frame):
    def __init__(self, parent=None):
        wx.Frame.__init__(self, parent, wx.ID_ANY)
            # set window icon
            if sys.platform == 'win32':
                # only do this on windows, so we don't
                # cause an error dialog on other platforms
                exeName = sys.executable
                icon = wx.Icon(exeName, wx.BITMAP_TYPE_ICO)
                self.SetIcon(icon)

if __name__ == '__main__':
    app = wx.App(redirect=False)
    frame = MyFrame()
    frame.Show(True)
    app.MainLoop()

Basically it uses sys.executable to find the exe we are running in and then gets wxPython to load the first icon it finds from it (which should be the icon of the executable itself). So when you run this directly from python (not packaged), you end up with the icon from the python executable, but when you run the packaged version you get the icon from the exe instead.

It includes the platform check, as otherwise the app throws up an error dialog on the mac and obviously I want this to work on both platforms (and Linux too in the future).