trying to write a simple python beaming snippet for Frescobaldi

[Leszek Wroński]

Guys,

Frescobaldi has the useful 'slur for the selected notes' snippet under C-(. I want to have the same functionality for beams. That is, I want to be able to select some notes, and then via the snippet insert a '[' in the first space (that is, after the first note), and then a ']' at the end.

Unfortunately, I have never in my life written a line of python... till this day, that is. So, I'm trying the following ('W' is for whitespace):

1 -*- name: mybeam; python; selection: strip;

2 x = 0

3 mysequence = text

4 while x < len(text):

5 WW if text[x] == ' ':

6 WWWW mysequence[x] = '['

7 WWWW break

8 WW x = x + 1

9 text = mysequence + ']'  

Notice that line 5 contains a space between the quotes. Of course I need to add conditions regarding what to do if there's no space in the selection etc. But that's for later, once this basic script actually works. As you can see, I thought I'd copy the selection to 'mysequence' string to manipulate on it; this is probably unneeded. But after writing the above I got, at line 5, an error "TypeError: 'unicode' object does not support item assignment".

What I found weird is that to my untrained eyes line 5 does no assigning, but rather checks whether the xth element of the string text is a space. Anyway, after some googling I decided to substitute "is" for "==" in line 5. Right now the script does not give any errors, but it only adds a ']' at the end of the selection. I'm apparently unable to check whether the xth element of the string text is a space. I tried

if text[x] == ' %d':

and

if text[x] ==  u"\u0020":

and

if text[x].isspace():

to no avail (the last one gave the "unicode object does not support item assignment" error again, which I don't understand at all, having copied the command from http://www.ehow.com/how_12112665_determine-character-whitespace-python.html). Could anyone give me a hint on this?

Best regards,

Leszek.