I wrote for some days on ozan(at)pardus.org.tr and get today the answer:
> can you please tell me how I build a pisi-package from source files (like .tar.gz or tar.bz2) ?
You can start by examining the pisi packages which are in our repositories:http://svn.pardus.org.tr/pardus/devel/
Just traverse through the directories and examine the structure of files.
The main elements of a pisi package are a specification file : "pspec.xml"
and an actions file : "actions.py".
The XML file contains important meta informations about the package like the URL of the source file to download, personal informations of the packager, list of patches to apply, list of dependencies, etc.
The actions file which is nothing more than a simple python script determines what to do in order to configure, build and install the package.
If there exists some additional files like patches, you put them in a directory named files/.