'Memo pad' : tech stuff

Py2xe: how to hide your GUI application error box "See the logfile for details"

2010-08-17T06:25:00.000-07:00

If for some reasons you need to hide that box while still logging the errors in myapp.exe.log, the following is a quick and dirty solution:

1) Find the file "boot_common.py" in your py2exe module (exemple: c:\python2x\Lib\site-packages\py2exe\boot_common.py) and make a backup copy in case of.

2) find the "def write" method and add a show_dialog parmeter this way:


def write(self, text, alert=sys._MessageBox, fname=sys.executable + '.log', show_dialog=False):

3) modify the following "else" block this way:


if show_dialog==True:
   import atexit
   atexit.register(alert, 0,"See the logfile '%s' for details" % fname,"Errors occurred")
else:
   pass

To come back to the original behavior change to "show_dialog=True" in 2).

More informations on Py2exe error handling here.

[french] Visualisation des séismes du RENASS via KML(s)

2008-06-22T06:54:00.000-07:00

(à partir des données du RENASS, Résau National de Surveillance Sismique )

Ce post est un "Google docs export" => page orginale à jour ici, dossier KML(s)

> KML des derniers tremblements de Terre

visualisez le KML (lien ci-dessus) dans Google Earth, World Wind, Virtual Earth, etc
derniers tremblements de Terre en premier dans la liste

> Visualisation dans Google Maps Search:

> Visualisation via Google Maps API:

> Visualisation via Open Layers sur carte Open Street Map:

Centré France

> Flux RSS pour se tenir au courant des derniers séismes (expérimental)

Flux RSS

Zoom

OSMaware, visualising OpenStreetMaps mapping activity via KML(s)

2008-05-30T07:32:00.000-07:00

More informations here: http://code.google.com/p/osmlab/

thanks for the "Lolcat of awesomeness" award :)

OS X 10.5 Leppard: "express" Python, PIL and WxPython please

2008-05-25T03:00:00.000-07:00

Python on OS X 10.5...

It is not recommended to mess-up with the Python 2.5 installed by default, and while wanting to install PIL and WxPython, I discovered and lost myself in the jungle of Python "distros" and their prerequisites (Fink, MacPorts, DarwinPorts, AciveState, MacPython ...)

In a hurry? go to the source: python.org (MacPython)

1) search and install the universal installer for OS X:
http://www.python.org/download/

This new Python will be the default one when you invoke "Python" in a shell.
It's installed in "/Library/Frameworks/Python.framework"
(the original OS X python is in: "/System/Library/Frameworks/Python.framework").
The new libs are in "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages"

2) download and install PIL, WxPython (or other packages) from:
http://pythonmac.org/packages/py25-fat

More informations about MacPython:
http://wiki.python.org/moin/MacPython

An interesting read about the Python distributions (especially in a scientific context)

Flex: how-to access remote data (xml) through a proxy?

2008-02-16T09:41:00.001-08:00

Flash player (used by Flex) has a very strict security policy: it's not possible to access public data from another domain than the one where your swf stands (unless a crossdomain.xml file is present on the distant server you want to access).

If the crossdomain file doesn't exist it is always possible to copy a minimal proxy file on your server (where your swf is present). This way flash player will communicate locally with the proxy, the proxy will give the result back to flashplayer, and there won't be any remote domain seen by flashplayer.

How-to use a proxy with Flex and Action Script3? (code and example)

http://docs.google.com/Doc?id=dgqhgsgm_154gfhwj5cn

How to programmatically draw in Flex 3?

2008-02-15T13:07:00.000-08:00

I was surprised by the lack of documentation( and working example) for this simple task.

Here's what I've got so far:

Flex doesn't like "Shape" objects? replace them with "UIcomponent"
a "UI component" must be attached to a container (like a canvas, a panel,...)
the shape will be visible when it is added has a child of the container: myCanvas.addChild(myCircle)

Here's an example with 3 buttons (1 to create a rectangle, 1 to create a circle, 1 to move them appart):

Run (right click at runtime then "view source" to see the code):
http://francois.schnell.free.fr/flex/draw/draw.html

Code in plain text:
http://docs.google.com/Doc?id=dgqhgsgm_153dc6cvzf7

Blogger: paste HTML, tags, code

2008-01-26T15:12:00.001-08:00

Blogger is not really code friendly. You need to "escape" each tag (replacing <>). Also spaces disappear and you may need to add a "pre" tag.

As I'm learning Flex/Air I've developed a small on-line tool to automate the process if you need to paste HTML or tags/code:

BloggerPaste:
http://francois.schnell.free.fr/tools/BloggerPaste/BloggerPaste.html

If you have any comments or feature request thanks to let me know.

Controlling Google Earth with Python (API COM)

2007-12-23T04:15:00.000-08:00

Google Earth is a powerful and beautiful application. Being able to control the globe, with few lines of Python code, makes you feel like you've got some god-like powers ;)

I've drafted here a short guide to show you how to start controlling Google Earth with Python (through its API COM):
http://docs.google.com/View?docid=dgqhgsgm_933rjw93

Wrap my head around unicode for Python

2007-12-22T13:20:00.000-08:00

Most interesting tutorial I've found: http://boodebr.org/main/python/all-about-python-and-unicode

Keypoints:

unicode are "symbols" or "objects" (no fixed computer representation, don't think bytes) and codecs transform them into binary strings (so you can print, store in disk, sent across network...).
a unicode string example with some greek characters: unicodeString = u"abc_\u03a0\u03a3\u03a9.txt"
you shouldn't 'print' a unicode string without encoding it first (by default Python will encode in ascii which can leads to errors if there are non ascii characters)
you can print a unicode "representation": print repr(unicodeString)
you encode with the .encode method: binary = unicodeString.encode("utf-8")
you can see the binary result like this: print "UTF-8", repr(unicodeString.encode('utf-8'))
print "ASCII",unicodeString.encode('ascii','replace') #will replace non-codable characters with '?'
from binary to unicode: unicode(utf8_string,'utf-8') # you must specify the encoding if not Python assumes it's ascii
once you have a Unicode object, it behaves exactly like a regular string object, so there is no new syntax to learn (other than the \u and \U escapes)

Iron Python Studio (Python, .Net and the power of Visual Studio for free)

2007-12-16T14:11:00.000-08:00

Iron Python Studio is a free IDE for Iron Python (Python for .Net).

You can develop command-line applications, Windows forms and WPF/XAML applications (see the project IronPythonScreenCast (wmv)).

Iron Python Studio has a visual designer for your GUI, code completion, debugger, etc (the usual tools of Visual Studio which makes in particular GUI development so simple).

It can use all the classes of .Net and also use the classic CPython (version 2.4 for now since this first version of the Studio is based on Iron Python 1.1)

More informations on my wiki note

[Win] Quick access to favorite folders

2007-05-20T10:03:00.000-07:00

"Folder Guide" is a handy windows freeware to keep the most common folders you use at your fingertip.

Folder Guide is a free handy utility that provides fast access to your frequently used and favorite folders. It can operate as the part of your context menu in your Windows Explorer.

[Python]: optparse -- powerful command line option parser

2007-03-03T11:01:00.000-08:00

I find optparse much better than getopt to get command line options.
The beast is explained here:
http://python.org/doc/lib/module-optparse.html

For example:

from optparse import OptionParser

parser=OptionParser()

parser.add_option("-f", "--file",dest="filename",help="a file to process")
parser.add_option("-r", "--repeat",dest="repeat",help="an integer")
parser.add_option("--dp",dest="directory",help="picture directory")
parser.add_option("-v",help="verbosemode",action="store_true",
dest="verbose",default=True)

(options,args)=parser.parse_args()

print options.filename
print options.repeat
print options.verbose
print options.directory

For flags, 'action' can be "store_true" or "store_false"

[Python]: find files of a certain type in a folder.

2007-03-03T08:52:00.000-08:00

To search for .jpg files in the folder "myfoder" you can do:


import os,fnmatch

for fileName in os.listdir ( "myfolder" ):
   if fnmatch.fnmatch ( fileName, '*.jpg' ):
       print "Found fileName ",fileName

Write GPS data on your photos with Exiftool

2007-02-26T10:43:00.000-08:00

Exiftool is a Windows/Mac command-line app (or a muti-plateform Perl librairy) to read and write EXIF metadatas on certain file types.

In the following I will use .jpg files from my camera and the Windows .exe version of Exiftool that I will control in a DOS shell.

Want to see some EXIF metadata in your picture ?

$ exiftool mypicture.jpg

Want to extract the precise date and time when this picture was taken ?

$ exiftool -CreateDate mypicture.jpg
( Returns something "2007:02:10 21:19:43")

Want to write your picture was on the Eastern part of Greenwich meridian ?

$ exiftool -GPSLongitudeRef="E" mypicture.jpg

Want to write the exact the longitude value ?

$ exiftool -GPSLongitude="7.422809" mypicture.jpg

Want to write your picture is in the northern latitudes ?

$ exiftool -GPSLatitudeRef="N" mypicture.jpg

and give the exact latitude value ?

$ exiftool -GPSLatitude="48.419973" mypicture.jpg

Obviously you can combine the four tags above in just one line.

You can check everything went well with another exiftool mypicture.jpg (warning: if the app. doesn't understand what to do it didn't return me any error message by default ).

More informations about the GPS tags can be found here.

With this Free Software GPL command-line version it's now easy to integrate geolacalisation capabilities in a Python script for example.

I can upload my pictures on Flickr and they will show on the Flick maps but I still need to use the geocoding bookmarklet if I want to add the geotagged tags and the google maps.

PS: -n option gives you the latitude/longitude in the decimal form when reading these tags
PS: Python also have a nice similar library but I didnt' succeed to write GPS data with it,
http://www.emilas.com/jpeg/

[Python] Callback examples with FTP

2007-02-21T00:53:00.000-08:00

From the wikipedia article:

In computer programming, a callback is executable code that is passed as an argument to other code. It allows a lower-level software layer to call a function defined in a higher-level layer.

Usually, the higher-level code starts by calling a function within the lower-level code passing to it a pointer or handle to another function. While the lower-level function executes, it may call the passed-in function any number of times to perform some subtask. In another scenario, the lower-level function registers the passed-in function as a handler that is to be called asynchronously by the lower-level at a later time in reaction to something.

Two examples with the FTP module of Python:

from ftplib import FTP

ftp = FTP("the_host")
ftp.login('ftpuser', 'ftppass')
ftp.cwd("folder")

# To obtain the list of files in a variable (not just the standard output) :

fileList=[]
command=ftp.retrlines("LIST",fileList.append)

# To download the file :

file = open("myfile.exe", 'wb')
ftp.retrbinary("RETR myfile.exe",file.write)
ftp.quit()
file.close()

[Python] How to get the output from os.system() into a variable ?

2007-02-20T09:28:00.000-08:00

A quick solution using popen :

import os
result=os.popen('command').read()
print result

where command is your command (expl. on windows: dir,ipconfig,...)

If you expect more than a line and want each word in a list:

import os,string
result=string.split(os.popen('dir/w').read())

Source of this

Clipboard and all-in-one system information for windows

2007-02-17T06:28:00.000-08:00

Two useful free software to complete my list of windows utilities :

Ditto is a very useful Open Source clipboard:

- history of text copies, images, screenshots
- enable hot keys, network sync, etc

SIW is a freeware which stands for "System Information for Windows"

- no installation required (can run on a USB key)
- hardware informations, temperature sensors, license keys, process, etc, etc.

[Python] Generating an html doc for your script(s)

2007-01-11T08:18:00.000-08:00

Pydoc
Python comes with a "pydoc" utility. On windows it is lacated in C:\Python2X\Lib (you may want to add this directory to your system path)

To produce an html documentation of a script or module type in a DOS shell (at the level of your script) :

pydoc.py -w nameOfYourScript

Warning:
- don't type the .py extension in the command above
- respect the uppercase and small caps even on windows.
- your script must have some docstrings

The above command produce a nameOfYourScript.html doc with the classes, methods, functions, etc.

Epydoc
For a more powerful and complete alternative I use the excellent Epydoc that you can download here:
http://epydoc.sourceforge.net/

On windows after the installation you can find the epydoc script in C:\Python2X\Scripts (you may want to add this directory to your system path)

To use epydoc just type in a shell in the folder containing your script(s):

epydoc.py scriptNameWithoutPyExtension

This will produce an "html" folder : read the index.html in your browser and enjoy :)

Firefox extensions

2007-01-04T00:36:00.000-08:00

A selection of useful Firefox extensions (updated 19 Fev 2007):

* Google Toolbar 3 (beta)
* Gutil a "Google Start Menu"
* Super DragAndGo for tabs
* Greasemonkey
* Flashblock
* gTranslate
* Key Scrambler
* Python Sidebar

Switching from a Linux to a Windows Desktop

2006-12-29T16:47:00.000-08:00

When I'm using a WinXP desktop I'm searching for an equivalent "Linux experience". Here's what I find useful so far (a mix of freeware and Free Software).

1) Look and feel

I don't like WinXP theme. CristalXP.net have great themes, wallpaper, icons, etc. I use the Microsoft "Royale Noir" a nice dark and sober theme.

Also very handy is iColorFolder to manage folders icons and the ability to quickly set their color for a better visual organisation.

You may also be interested by a Virtual Desktops Manager or want to access the "contextual" command line window from a right click on a folder or maybe to customize completely you're right click menu.

2)Shell and processes

This was the weakest point of winXP for me. Microsoft now released Power Shell and I must admit I find it good (it is just a little long to start). There are also aliases for usual Linux command (ls, pwd, cd /, etc) but I think Power Shell commands are very neat and clear.

Also, if you want to see the running processes in a graphical way Process Explorer is a great tool to replace the Task manager.

3)Copy/Paste and Screenshots

WinXP doesn't keep an history of your cut and paste actions and this can result in a loss of data. Cliptray is a freeware which solve this problem.

Linux distros always come with handy screenshots utilities. Cliptray can also do it but I prefer to use irfanview (tuto).

4)Security

Microsoft OS is unfortunately a big target. Apart from an antivirus and a firewall I feel safer to use Firefox and this KeyScrambler extension against eventual data loggers for login/passwords.

5)Applications

Software are not a problem since I'm using either web services (gmail, google reader,etc) and/or multi platform software (Vim,Python,OOo,Firefox,etc).

Also to work with a Linux PC or server Putty and WinSCP are a must.

[win] Visualize your Hard Drive and more

2006-12-24T13:35:00.000-08:00

WinDirStat for windows is an excellent Free utility (GPL):

- visualize disk usage per folder of per file types
- click on a box (file or folder) for properties, edition commands, contextual explorer or command prompt

A really nice and useful tool to organize and know more about what's really on your Hard Drive.

http://windirstat.info/

[Python]: Introspection with help()

2006-12-18T22:31:00.000-08:00

An article on this subject

Let's say for example I want to integrate a FTP client in my script and I don't want to lose time searching in books or on the web.

Humm, I'm not sure which lib to use ?

>>> help('modules') #gives a list of all the modules

Oh "ftblib" could be useful, lets check

>>> import ftplib
>>> help(ftplib) # gives a description of this module with the classes, etc.

=> the class "FTP" is what I need for the client part

>>> help(ftplib.FTP) # if I just want to see the description of the FTP class

For more informations about 'help' just type help() at the Python prompt.

Another way to find documentation if you are on-line is to use the Python Sidebar in Firefox.

Wii remote : a powerful tool

2006-12-17T09:12:00.000-08:00

Why the wii remote is cool.

Few tech links :

[Python] How-to: hide the source code when distributing a Python script ?

2006-12-16T12:50:00.000-08:00

Create a .pyc file with your script:

>>> import py_compile
>>> py_compile.compile('myscript.py')

This will produce myscript.pyc (c for compiled) that you can distribute instead of the .py (python will run the .pyc).

[Python] How-to: hide the console

2006-12-16T12:49:00.001-08:00

Solution 1 :

Rename the .py file in .pyw (w for window)

Solution 2:

Use' pythonw' instead of Python to launch the script.

This second solution is useful if you have a pyc file : create a shortcut and in it open the file with pythonw (the pyc file won't open a console)

[Ubuntu] How-to boot windows by default

2006-12-16T12:47:00.001-08:00

After a fresh Ubuntu install, on a Windows PC, the Grub boot loader put Linux as the default system.

To change the default OS (Windows to boot first in our case):

edit the menu.lst file (in /boot/grub) with root rights.
For example with the Vim editor in a shell:
sudo vim /boot/grub/menu.lst

find and change "default 0" to "default X" where X is the "position" of the Windows OS in the list presented by Grub at boot time (count the "title"s/lines beginning with X=0 for the first line)

Using Vim without the arrow keys

2006-12-16T12:44:00.000-08:00

I've used a Linux laptop where the arrow keys don't behave as excepted in Vim and was then forced to learn the equivalent keys.

h: a char back
j: a line down
k: a line up
l: a char forward

All this is accessible from the right hand and leave the left one free to reach the escape key to change mod.

Handy, I begin to like it :)

More informations here and here

EDIT:
Funny, I also discovered that the excellent Google Reader have j and k short-cuts to go down or up on the RSS list :)

[Win] Command line : recording a live video from a webcam or another video device

2006-12-16T12:22:00.001-08:00

I use Microsoft Windows Media Encoder 9 Series which is free as in beer (I didn't need to download the free SDK).

In "Program Files\Windows Media Components\Encoder" it installs in particular a script called WMCmd.vbs.

You can run this script with cscript.exe which should already be in "Windows\system32" :

cscript.exe WMCmd.vbs -adevice X -vdevice Y -output C:\test.wmv -duration Z

where,

X= the number of the audio device (I used 1 in my case for my webcam)
Y= the number of the video device (I also used 1 for my webcam here)
Z= the duration in seconds (you can always kill the process on the go if the video is shorter)

For command-line options type "cscript.exe wmcmd.vbs" in the shell.

If I want the video to be shorter than the given duration and want to control this from a Python script I use the DOS taskkill command.

More informations also here.

[Win] Video/Audio conversion with MMconvert

2006-12-07T22:31:00.000-08:00

I'm searching for a tool to convert videos on Windows (in particular wmv) in a more open format. I also need a command line control (for later Python scripting).

A quick search on SourceForge brings me a first tool : MMconvert

In its installation folder there are MMconvert.exe (for command line) and MMConvertGUI (with a GUI ...)

The GUI version:

- choose the video container in "Video Operations" (I have avi, wmv,mkv)
- "add" one or more video to convert
- select the video and audio codecs to use, "ok" -> "execute"

Command line version:

Let say I want to convert my wmv into a matroska (mkv).

First I check for the audio and video codecs that I have on my computer (and that I can use with this container):
MMconvert.exe /f:mkv /lv
MMconvert.exe /f:mkv /av

This commands gives a list of codecs I can use for the matroska container (just remember the associated number, X and Y in the following).

To convert the video:
MMconvert.exe if=test.wmv of=test.mkv /f:mkv /v:X /a:Y

Memo:
if= input file
of=output file
f=format (for the container: avi,wmv,mkv...)
v=video
a=audio

To know more about the aguments : mmconvert.exe /?

It looks like a great tool but I haven't found yet if I can hide the little "Status windows" in command-line mod. I don't see either if I can play with the bitrate

What is this ... "Blog" ??

2006-12-05T12:25:00.000-08:00

This is more a 'Memo pad' about *technical* stuff than a Blog: I put here fragments of memories, recipes, links, ideas I want to explore, to do, etc.

It's messy, possibly won't be useful to you, but it helps the "externalization of my cognitive functions" (through the search function + permanent web access). There is no password to keep my synaptic delay short ;)

Everything here is in a 'draft'-state