simple package to use gmsh via the original gmsh_api (https://gitlab.onelab.info/gmsh/gmsh/blob/master/api/gmsh.py, https://gmsh.info/bin/Linux/gmsh-X.Y.Z-Linux64-sdk.tgz).
Christophe Geuzaine is a hero.
# gmsh_api package with some useful classes
import gmsh_api
# original gmsh-api from gmsh package
import gmsh_api.gmsh as gmsh
gmsh.initialize()
gmsh.option.setNumber("General.Terminal", 1)
gmsh.option.setNumber("Mesh.Algorithm", 5) # delquad
gmsh.option.setNumber("Mesh.RecombineAll", 1)
gmsh.model.add("square")
gmsh.model.geo.addPoint(0, 0, 0, 0.6, 1)
gmsh.model.geo.addPoint(1, 0, 0, 0.6, 2)
gmsh.model.geo.addPoint(1, 1, 0, 0.5, 3)
gmsh.model.geo.addPoint(0, 1, 0, 0.4, 4)
gmsh.model.geo.addLine(1, 2, 1)
gmsh.model.geo.addLine(2, 3, 2)
gmsh.model.geo.addLine(3, 4, 3)
# try automatic assignement of tag
line4 = gmsh.model.geo.addLine(4, 1)
gmsh.model.geo.addCurveLoop([1, 2, 3, line4], 1)
gmsh.model.geo.addPlaneSurface([1], 6)
gmsh.model.geo.synchronize()
gmsh.model.mesh.generate(2)
#gmsh.write("square.unv")
mesh = gmsh_api.Mesh.from_gmsh(gmsh)
print(mesh.nodes)
print(mesh.elements)
nid x y z
1 1 0 0 0
2 2 1 0 0
3 3 1 1 0
4 4 0 1 0
5 5 0.5 0 0
6 6 1 0.522774 0
7 7 0.728708 1 0
8 8 0.472136 1 0
9 9 0.229485 1 0
10 10 0 0.786636 0
11 11 0 0.55051 0
12 12 0 0.289194 0
13 13 0.267268 0.304987 0
14 14 0.703727 0.740444 0
15 15 0.387068 0.62141 0
16 16 0.637319 0.370788 0
17 17 0.189356 0.818467 0
pid elid type n_nodes nodes nidxs
0 1 17 shell4 4 [9L, 17L, 15L, 8L] [9L, 17L, 15L, 8L]
1 1 18 shell4 4 [15L, 17L, 10L, 11L] [15L, 17L, 10L, 11L]
2 1 19 shell4 4 [10L, 17L, 9L, 4L] [10L, 17L, 9L, 4L]
3 1 20 shell4 4 [5L, 16L, 15L, 13L] [5L, 16L, 15L, 13L]
4 1 21 shell4 4 [6L, 14L, 15L, 16L] [6L, 14L, 15L, 16L]
5 1 22 shell4 4 [6L, 16L, 5L, 2L] [6L, 16L, 5L, 2L]
6 1 23 shell4 4 [15L, 14L, 7L, 8L] [15L, 14L, 7L, 8L]
7 1 24 shell4 4 [15L, 11L, 12L, 13L] [15L, 11L, 12L, 13L]
8 1 25 shell4 4 [5L, 13L, 12L, 1L] [5L, 13L, 12L, 1L]
9 1 26 shell4 4 [6L, 3L, 7L, 14L] [6L, 3L, 7L, 14L]