[PyQt] Question about QsciLexerCustom

[projetmbc]

Hello,
I would like to use QsciLexerCustom so as to define my own lexer. The 
documentation says :
             "All that is necessary to implement a new lexer is to 
define appropriate
              styles and to re-implement the styleText() 
<classQsciLexerCustom.html#91d71c4bdff5140ae0b0cb34b4511f79> method."
This sounds very abstract to me. How can I color a single word like 
STRANGE ? How can I define a block like a C++ comment ?


Best regards.
Christophe

PS : I'm ready to do a simple but complete PyQt example that could help 
future users but for the moments I do not how to start.