[Gmsh] How to create Surface from Discrete surface ?

[Kenneth Assogba]

Dear GMSH developer,

I'm using Gmsh Python API in version 4.5.6. I have some .msh file (with
just points and line who define a surface) and I a want to create a 2D mesh
on it. As it is not directly possible, i'm triying the
*gmsh.model.mesh.createGeometry()* method and after that, doing
*gmsh.model.geo.synchronize()*
*gmsh.model.mesh.generate(2)*

The result in the console is :
Info    : Creating geometry of discrete curves...
Info    : Done creating geometry of discrete curves (8e-06 s)
Info    : Creating geometry of discrete surfaces...
Info    : Done creating geometry of discrete surfaces (1e-06 s)

But the 2D mesh isn't create. Do you have any idea of how I can do ?
I see here (t13)
<https://gitlab.onelab.info/gmsh/gmsh/-/blob/master/tutorial/python/t13.py>
that you recreate surface loop and volume before mesh, but in my case it is
not possible since Gmsh return the error : Error   : GEO surface with tag 1
already exists.

By reading information about the file (explore)
<https://gitlab.onelab.info/gmsh/gmsh/-/blob/master/demos/api/explore.py>,
I can see:
Entity (2, 1) of type Discrete surface
 - Mesh has 0 nodes and 0 elements
 - Boundary entities: [(1, 1), (1, 2), (1, 3), (1, 4)]

Please see attached the original .geo and the exported .msh.

Thank you in advance,
Best regards,

Kenneth Assogba
Master 2 Ingénierie Mathématique Pour l'Entreprise
Sorbonne Université - Faculté de Sciences et Ingénierie
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