@stef.rausch In fact the templater doc is quiet poor. I found the <%+* command in the forum (Templater plugin (1.5 and newer): New Syntax and Examples - #20 by Moonbase59)
I also assume that the command should be in one line, from personal experiments and all exemples I could found.
@Yurcee : I found in gitlab issues that <%* has been deprecated, which seems right as no code inside <%* wrapper is working within my environment.
I succeed in creating a markdown table with external python code. I didn’t know about dataview and its capabilities in using regex. Thanks for pointing it to me @holroy. I may investigate this way.