Demi flèche / half arrow

Thanks for answer, i don't know python, but i try this solution.
For information it is to do origami diagram like this:
http://www.passion-origami.com/images/Image/File/DELALANDRE/Gland%20by%20Jean-Jacques%20DELALANDRE.pdf
and i need half-arrow for describe specific action.
JJD

PS: sorry fo my badely english

Sorry it's not python lol
I hve look in the markers.svg file, and i think it is the good way.
 i try to do half-arrow in stating existing arrow.
JJD

Wonderfull, i have add this code in the "markers.svg" file:

        <!-- 1 half arrow -->
  <marker style="overflow:visible" id="Half-Arrow1Lstart" refX="0.0" refY="0.0" orient="auto" inkscape:stockid="Half-Arrow1Lstart">
      <path transform="scale(0.8) translate(12.5,0)" style="fill-rule:evenodd;stroke:#000000;stroke-width:1.0pt;marker-start:none" d="M 0.0,0.0 L 5.0,-5.0 L -12.5,0.0 z "/>
    </marker>

to do it i proced like this:

I have make a copy of one existing arrow:
    <!-- 1 Medium -->
    <marker style="overflow:visible" id="Arrow1Mstart" refX="0.0" refY="0.0" orient="auto" inkscape:stockid="Arrow1Mstart">
      <path transform="scale(0.4) translate(10,0)" style="fill-rule:evenodd;stroke:#000000;stroke-width:1.0pt;marker-start:none" d="M 0.0,0.0 L 5.0,-5.0 L -12.5,0.0 L 5.0,5.0 L 0.0,0.0 z "/>
    </marker>

I change the "id" and "inkscape:stockid" to "Half-Arrow1Lstart"
and i have modified
 d="M 0.0,0.0 L 5.0,-5.0 L -12.5,0.0 L 5.0,5.0 L 0.0,0.0 z "
to
 d="M 0.0,0.0 L 5.0,-5.0 L -12.5,0.0 z

I save athe file nd restart inskape, and it is magic, i have my alf-arrow

it is exactly that i needed, thanks you mahfiaz

Thanks mahfiaz, that solved my question.