How to change or recreate your Desktop folder on Ubuntu

The default location of your Desktop folder is ~/Desktop. You might prefer another location. If you by accident deleted the Dekstop folder, it will be stuck in your Trash folder as you can't put it back. These two steps enable you to change or restore your desktop folder:

gedit ~/.config/user-dirs.dirs
killall nautilus

In step 1 look for this entry: XDG_DESKTOP_DIR. Make it like this: XDG_DESKTOP_DIR="$HOME/Desktop"
Instead of step 2 you might also log off and log in again.

This is only tested on Gutsy.

How to install pymedia on Ubuntu (Gutsy)

"Pymedia is a Python library for accessing and manipulating media files. It makes audio and video playback/creation a snap for even a newcomer to programming." There is a deb installer available for pymedia 1.3.5 but not for 1.3.7 So I decided to write this howto.

First install all the dependencies:

sudo apt-get install python-dev libogg-dev libvorbis-dev liblame-dev libfaad2-dev libasound2-dev python-pygame

(Pygame is not really necessary, but recommended.)

Extract a download of pymedia-*.tgz and open a terminal in the extracted folder, so we can build pymedia:

python setup.py build

This should display:

Using UNIX configuration...

OGG : found
VORBIS : found
FAAD : found
MP3LAME : found
VORBISENC : found
ALSA : found
Continue building pymedia ? [Y,n]:

If everything is found press Y

Finally install pymedia:

sudo python setup.py install

Test if pymedia installed correctly by typing this at the python shell:

import pymedia

You may now proceed to the pymedia tutorials.

SPE 0.8.4.b works fine in Ubuntu Gutsy

The latest version of SPE 0.8.4.b works very well in Ubuntu Gutsy. It is available through subversion. However the repository package is outdated, as it is still on 0.8.2.a What SPE needs to solve this issue is a Debian packager with love for python. This is the related bug on launchpad, from which I quote Scott:
"Ubuntu gets this package from Debian and it appears that it's been orphaned in Debian.
(...) it'd be hugely helpful if someone concerned about spe would adopt it in Debian. There is a Debian Python Applications Team with active DD support, so you need not be a DD to do this."
If you are not a packager it would be nice if you leave your comment on the launchpad bug.
https://bugs.launchpad.net/ubuntu/+source/spe/+bug/124896
So this gets more attention and will be fixed sooner as there is more demand. If someone steps up to package this for debian, I will release a new version of SPE.

Winpdb 1.2.2, wxGlade0.6 & XRCed 0.1.8-5...

...all landed in subversion (rev255). wxGlade and XRCed are taken from their repositories, so they might be bleeding edge. Thanks to Diaa Sami some issues on Windows are fixed (eg running files with spaces). Check out the new SPE in the usual way:

svn checkout svn://svn.berlios.de/python/spe/trunk/_spe

Latest wxGlade in SPE subversion

I've uploaded the latest wxGlade cvs into the subversion repository of SPE.

Last WinPdb debugger 1.0.9 in SPE subversion

The last version of WinPdb debugger 1.0.9 has hit the SPE 0.8.4 subversion repository. What is now especially nice is that when you debug a python file from SPE, WinPdb remembers it when you have to relaunch the script. In case you don't know WinPdb:

Winpdb is a GPL python debugger, with support for smart breakpoints, multiple threads, namespace modification, embedded debugging, password encrypted communication and speed of up to 20 times that of pdb.

What I like especially about WinPdb, is that it is perfect for gui debugging as it supports multiple threads, that you can change variables on the fly (with exec variable=new_value in the shell) and... the amazing speed for a debugger. It almost runs programs at normal speed. SPE gives you the option to start running a program normally and to let WinPdb break in from the moment you want to debug. WinPdb has been fixed for Ubuntu and Mac, so now it is the best open source python debugger for Linux, Mac and Windows.

These are all the changes of 1.0.9:

• Bug fix of bug 1654010 - window gets bigger on every session.
• Bug fix of bug 1373074 - 2 Window menus on mac.
• Bug fix of bug 1654011 - clipping long path names at the left.
• Bug fix of bug 1654009 - List indices are sorted wrong.
• Bug fix of bug 1610393 - Problems with wx-2.7.2-msw-unicode.
• Bug fix of bug 1481097 - "# -*- coding: " problem.
• + fixes for tons of unreported bugs.
• Feature request 1654155 - More compact variable list on OS X.
• Feature request 1446799 - Restarting.
• Feature request 1364935 - remember command line file.

In the latest release of SPE 0.8.3.c shipped with Winpdb 1.0.6 , so the changes of WinPdb might interest you as well:

• Bug fix of bug 1358842 - Wrong terminal command in RHEL4.
• Bug fix of bug 1559668 - not work with Ubuntu Dapper 6.06.
• Bug fix of bug 1476311 - script launch fails with gnome-terminal.
• Bug fix of bug 1492500 - Filtering should work anywhere.
• Bug fix of bug 1445514 - Doesn't work with *.pyw scripts.
• Bug fix of bug 1491470 - Slightly difficult to use a custom terminal in rpdb2.
• Bug fix of bug 1546181 - Sort names alphabetically.
• Bug fix of bug 1481097 - "# -*- coding: " problem.
• Fixed exception handling on CPython 2.4.x and CPython 2.5.
• Fixed some compatibility issues with wxPython 2.7.

SPE: Call for testers!

I've been working a lot on fixing SPE and upgrading it with the latest plugins. The winpdb debugger no longer fails and wxGlade crashes are history. Is that not great? Are you eager to try it out yourself? Please do! Get it from subversion and test it for any critical bug, so I can iron it out. I have been patching a lot for Ubuntu users, who will be very pleased with this release, and I'd like to thank Jurjen a lot for his work on Mac issues. This is a definitely a release everyone should upgrade to, wether you use windows, mac or linux!

Here is an overview what has been done:

The focus in this release is bugfixing, plugin upgrades and compatibility with wxPython 2.8, but it also still works on wxPython 2.6

Upgrades:
- WinPdb to 1.0.8 (not fail in timely manner anymore)
- wxGlade to latest cvs (support for wxWindows2.8)

New features:
- Save as copy
- Clear output pane

Fixes
- output: escape html characters in tab & respect spaces
- preserve file permissions and avoid erasing file
- wxversion handling at startup
- font dialog
- recent files sorted by lowercase
- default buttons on all dialog
- mac: run terminal commands (jurjen)
- mac: pychecker
- ubuntu: switch to file
- some critical bug fixes which could have crashed SPE in the past
- much more ...

PS. Winpdb does not work well on Mac & wxpython2.8 Nir is working on an update. So when it comes out it will be included with SPE.

Pyxides brainstorm: generic 'fold explorer'

I posted on the pyxides mailing list a prototype of a 'fold explorer'. A fold explorer is different from a class explorer as it shows the folding hierarchy of a document as a tree. Why? The aim is to use the internal power of Scintilla as much as possible. Scintilla supports 78 languages and a lot of them with folding. So the fold explorer enables any scintilla based editor to immediately support a whole range of languages. The fold explorer is also able to detect the start and end line of a node. If you right click any item in the tree, it will select the corresponding source. So later it should be possible with drag and drop items in a tree to reorganise your code. (Like in Leo, but without comments.) Now it uses 'picasso', a random style colorizer. For more information read the this thread on the pyxides mailing list. (Join the mailing list!)

Does anyone know how with python I could dynamically retrieve if a language support folding? That is the last missing piece.

This screenshot shows how it parses its own python source:


Rob McMullen shows how it parses a C++ file:


Here is the source code if you want to try it out for yourself. You need to have wxPython installed to run it. It is a nice demo if you want to play around with scintilla on python. I am open to any improvements, remarks or feedback.

#!usr/bin/python              
# -*- coding: utf8 -*-        
#(c)www.stani.be, GPL licensed

import sys, random
import wx
import wx.stc as stc

DEFAULT_ENCODING= 'utf8'
STC_LANGUAGES   = [x[8:] for x in dir(stc) if x.startswith('STC_LEX_')]
WHITE           = 6777215
GRAY            = 3388607

def value2colour(c):
    return ('#%6s'%hex(c)[2:]).replace(' ','0').upper()

def picasso():
    c   = random.randint(0,GRAY)
    return value2colour(c), value2colour((c+GRAY)%WHITE)

class Node:
    def __init__(self,level,start,end,text,parent=None,styles=[]):
        """Folding node as data for tree item."""
        self.parent     = parent
        self.level      = level
        self.start      = start
        self.end        = end
        self.text       = text
        self.styles     = styles #can be useful for icon detection
        self.children   = []
        

class Editor(stc.StyledTextCtrl):
    #---initialize
    def __init__(self,parent,language='UNKNOWN'):
        stc.StyledTextCtrl.__init__(self,parent,-1)
        self.setFoldMargin()
        self.encoding   = DEFAULT_ENCODING
        
    def setFoldMargin(self):
        self.SetProperty("fold", "1")
        self.SetProperty("fold.html","1")
        #MARGINS
        self.SetMargins(0,0)
        #margin 1 for line numbers
        self.SetMarginType(1, stc.STC_MARGIN_NUMBER)
        self.SetMarginWidth(1, 50)
        #margin 2 for markers
        self.SetMarginType(2, stc.STC_MARGIN_SYMBOL)
        self.SetMarginMask(2, stc.STC_MASK_FOLDERS)
        self.SetMarginSensitive(2, True)
        self.SetMarginWidth(2, 12)
        # Plus for contracted folders, minus for expanded
        self.MarkerDefine(stc.STC_MARKNUM_FOLDEROPEN,    stc.STC_MARK_MINUS, "white", "black")
        self.MarkerDefine(stc.STC_MARKNUM_FOLDER,        stc.STC_MARK_PLUS,  "white", "black")
        self.MarkerDefine(stc.STC_MARKNUM_FOLDERSUB,     stc.STC_MARK_EMPTY, "white", "black")
        self.MarkerDefine(stc.STC_MARKNUM_FOLDERTAIL,    stc.STC_MARK_EMPTY, "white", "black")
        self.MarkerDefine(stc.STC_MARKNUM_FOLDEREND,     stc.STC_MARK_EMPTY, "white", "black")
        self.MarkerDefine(stc.STC_MARKNUM_FOLDEROPENMID, stc.STC_MARK_EMPTY, "white", "black")
        self.MarkerDefine(stc.STC_MARKNUM_FOLDERMIDTAIL, stc.STC_MARK_EMPTY, "white", "black")
        self.Bind(stc.EVT_STC_MARGINCLICK, self.onMarginClick)
            
    def onMarginClick(self, evt):
        # fold and unfold as needed
        if evt.GetMargin() == 2:
            if evt.GetShift() and evt.GetControl():
                self.FoldAll()
            else:
                lineClicked = self.LineFromPosition(evt.GetPosition())
                if self.GetFoldLevel(lineClicked)&stc.STC_FOLDLEVELHEADERFLAG:
                    if evt.GetShift():
                        self.SetFoldExpanded(lineClicked, True)
                        self.Expand(lineClicked, True, True, 1)
                    elif evt.GetControl():
                        if self.GetFoldExpanded(lineClicked):
                            self.SetFoldExpanded(lineClicked, False)
                            self.Expand(lineClicked, False, True, 0)
                        else:
                            self.SetFoldExpanded(lineClicked, True)
                            self.Expand(lineClicked, True, True, 100)
                    else:
                        self.ToggleFold(lineClicked)
                        
    #---open
    def open(self,fileName, language, encoding=DEFAULT_ENCODING, line=0):
        self.setLanguage(language)
        self.setText(open(fileName).read(),encoding)
        wx.CallAfter(self.GotoLine,line)
                        
    def setText(self,text,encoding=DEFAULT_ENCODING):
        self.encoding   = encoding
        self.SetText(text.decode(encoding))
        self.Colourise(0, self.GetTextLength()) #make sure everything is lexed
        wx.CallAfter(self.explorer.update)
        
    def setLanguage(self,language):
        if language in STC_LANGUAGES:
            self.SetLexer(getattr(stc,'STC_LEX_%s'%language))
            for style in range(50):
                self.StyleSetSpec(style,"fore:%s,back:%s"%picasso())
            return True
        return False
    
    #---hierarchy
    def getHierarchy(self):
        #[(level,line,text,parent,[children]),]
        n               = self.GetLineCount()+1
        prevNode = root = Node(level=0,start=0,end=n,text='root',parent=None)
        for line in range(n-1):
            foldBits    = self.GetFoldLevel(line)
            if foldBits&stc.STC_FOLDLEVELHEADERFLAG:
                #folding point
                prevLevel       = prevNode.level
                level           = foldBits&stc.STC_FOLDLEVELNUMBERMASK
                text            = self.GetLine(line)
                node            = Node(level=level,start=line,end=n,text=text)
                if level == prevLevel:
                    #say hello to new brother or sister
                    node.parent = prevNode.parent
                    node.parent.children.append(node)
                    prevNode.end= line
                elif level>prevLevel:
                    #give birth to child (only one level deep)
                    node.parent = prevNode
                    prevNode.children.append(node)
                else:
                    #find your uncles and aunts (can be several levels up)
                    while level < prevNode.level:
                        prevNode.end = line
                        prevNode  = prevNode.parent
                    node.parent = prevNode.parent
                    node.parent.children.append(node)
                    prevNode.end= line
                prevNode        = node
        prevNode.end    = line
        return root
    
    def selectNode(self,node):
        """If a tree item is right clicked select the corresponding code"""
        self.GotoLine(node.start)
        self.SetSelection(
            self.PositionFromLine(node.start),
            self.PositionFromLine(node.end),
        )
        
class TreeCtrl(wx.TreeCtrl):
    def __init__(self,*args,**keyw):
        keyw['style'] = wx.TR_HIDE_ROOT|wx.TR_HAS_BUTTONS
        wx.TreeCtrl.__init__(self,*args,**keyw)
        self.root        = self.AddRoot('foldExplorer root')
        self.hierarchy  = None
        self.Bind(wx.EVT_RIGHT_UP, self.onRightUp)
        self.Bind(wx.EVT_TREE_KEY_DOWN, self.update)
        
    def update(self, event=None):
        """Update tree with the source code of the editor"""
        hierarchy   = self.editor.getHierarchy()
        if hierarchy != self.hierarchy:
            self.hierarchy = hierarchy
            self.DeleteChildren(self.root)
            self.appendChildren(self.root,self.hierarchy)
    
    def appendChildren(self,wxParent,nodeParent):
        for nodeItem in nodeParent.children:
            wxItem    = self.AppendItem(wxParent,nodeItem.text.strip())
            self.SetPyData(wxItem,nodeItem)
            self.appendChildren(wxItem,nodeItem)
            
    def onRightUp(self,event):
        """If a tree item is right clicked select the corresponding code"""
        pt              = event.GetPosition();
        wxItem, flags   = self.HitTest(pt)
        nodeItem        = self.GetPyData(wxItem)
        self.editor.selectNode(nodeItem)

class Frame(wx.Frame):
    def __init__(self,title,size=(800,600)):
        wx.Frame.__init__(self,None,-1,title,size=size)
        splitter            = wx.SplitterWindow(self)
        self.explorer       = TreeCtrl(splitter)
        self.editor         = Editor(splitter)
        splitter.SplitVertically(
            self.explorer,
            self.editor,
            int(self.GetClientSize()[1]/3)
        )
        self.explorer.editor    = self.editor
        self.editor.explorer    = self.explorer
        self.Show()
    
if __name__ == '__main__':
    print 'This scintilla supports %d languages.'%len(STC_LANGUAGES)
    print ', '.join(STC_LANGUAGES)
    app     = wx.PySimpleApp()
    frame   = Frame("Fold Explorer Demo")
    
    fileName= sys.argv[-1]                      #choose file
    frame.editor.open(fileName,'PYTHON','utf8') #choose language in caps
    
    app.MainLoop()

How to switch between python2.4 and python2.5 on Ubuntu

The default version of python on Edgy is python2.4 and on Feisty is python2.5 If you installed both versions of python and want to switch between them you have once to type this in a terminal:

sudo update-alternatives --install /usr/bin/python python /usr/bin/python2.4 10
sudo update-alternatives --install /usr/bin/python python /usr/bin/python2.5 1

Afterwards you can choose at any time your standard python version by:

sudo update-alternatives --config python

SPE now works on wxPython2.8 and how to switch

Today I switched on my laptop from wxPython2.6 to wxPython2.8 SPE seemed to work quite OK already, except: the bottom panel took too much place and was not draggable to a smaller size. After fixing this annoying bug, I am happily coding now with SPE on wxPython 2.8 For those who want to try out before I release, follow the subversion instructions. I tested the new SPE on Ubuntu (wxPython 2.6 & 2.8) and on Windows (wxPython 2.8). If anybody knows a good subversion client for the Mac, please comment.

sudo wxPython 2.8 has major new features such as AUI (Advanced User Interface), anti-alias graphics (Graphicscontext) and a lot of new widgets (RichTextCtrl, CustomTreeCtrl, SearchCtrl a la Firefox, ...). This might be useful for SPE in the future, but at the moment SPE stays backwards compatible with wxPython 2.6.


On Feisty wxPython is already included in repositories, just type:

sudo apt-get install python-wxgtk2.8

On Edgy you need to use the wxPython coummunity repositories. Open /etc/apt/sources.list:

sudo gedit /etc/apt/sources.list

Add the following lines:

# wxPython APT repository at wxcommunity.com
deb http://wxpython.wxcommunity.com/apt/ubuntu/dapper /
deb-src http://wxpython.wxcommunity.com/apt/ubuntu/dapper /

Then copy and paste these lines in a terminal:

sudo apt-get update
sudo apt-get dist-upgrade
sudo apt-get install python-wxgtk2.8 python-wxtools wx2.8-i18n

If you want to use XRC gui designer, you need python-xml:

sudo apt-get install python-xml

How to download the latest SPE from subversion

If you want to have the latest version of SPE, use subversion which is very easy. (Subversion is a way for multiple people around the world to work on the same program. It keeps the changes that they make to the source code of that program in sync with each other.) Do not forget first to uninstall your previous version of SPE! Windows users can uninstall SPE through 'Add/Remove programs' in the Control Panel (look for 'python-spe*', not for 'spe') and use a subversion client (tortoisesvn, rapidsvn) to get the latest SPE. Linux and mac users need just to copy and paste this in the terminal:

svn checkout svn://svn.berlios.de/python/spe/trunk/_spe

This will create a '_spe' folder. (Do not rename it to 'spe' or another name!) From this folder you can run:

python SPE.py

To browse the subversion repository online, surf to:

http://svn.berlios.de/wsvn/python/spe/trunk/_spe/

For ubuntu: to first remove SPE, type this in the terminal:

sudo apt-get remove spe kiki wxglade

To install subversion (svn), type this in the terminal:

sudo apt-get install subversion

Instructions for Tortoise SVN (thanks Richard):

1. Go to the location you want to download SPE to
2. Right click -> SVN Checkout
3. Paste svn://svn.berlios.de/python/spe/trunk/_spe into the url field
4. Click ok and it should work.

Switched from Windows to Ubuntu

I've switched from Windows to Ubuntu since half a year and I don't look back. I can recommend every python developer to do the same as the batteries included in Ubuntu are a python paradise. Of course I will continue supporting SPE on Windows and Mac as well. Watch out this blog as I will post here updates about SPE and some useful things about python, Ubuntu, UML, ...