OpenMesh Python cheat sheet https://openmesh-python.readthedocs.io/en/latest/

openmesh-python-cheat-sheet.py

# OpenMesh-Python Cheat Sheet
'''
documentation: https://openmesh-python.readthedocs.io/en/latest/
OpenMesh-Python official repository:
  https://www.graphics.rwth-aachen.de:9000/OpenMesh/openmesh-python
C++ documentation:
  https://www.openmesh.org/media/Documentations/OpenMesh-Doc-Latest/a04099.html

Installation:
* pip install openmesh  # https://pypi.org/project/openmesh/
* conda install -c conda-forge openmesh-python  # https://anaconda.org/conda-forge/openmesh-python/
This is NOT https://anaconda.org/conda-forge/openmesh/
'''
import openmesh


# File IO
# file formats: obj, off, om, ply, stl, vtk (only write)
mesh = openmesh.read_trimesh('filename.obj')  # or read_polymesh
# Options:
#  binary, msb, lsb, swap,
#  vertex_normal, vertex_color, vertex_tex_coord,
#  halfedge_tex_coord, edge_color,
#  face_normal, face_color, face_texture_index,
#  color_alpha, color_float
# obj texture:
#  texture_file="moon.png",
#  material_file_extension=".mtl" 

openmesh.write_mesh('filename.obj', mesh)
# The same options as read_trimesh, except for face_texture_index

# Geometry Elements and Standard Properties
mesh.n_vertices()                        # number of elements
mesh.n_edges()
mesh.n_faces()
mesh.n_halfedges()
point_array = mesh.points()              # get element array
face_array = mesh.face_vertex_indices()
color_array = mesh.vertex_colors()  # n x 4
mesh.vertex_normals()
mesh.vertex_texcoords1D()  # vertex_texcoords2D vertex_texcoords3D
mesh.halfedge_normals()
mesh.halfedge_colors()
mesh.halfedge_texcoords1D()  # halfedge_texcoords2D() halfedge_texcoords3D()
mesh.edge_colors()
mesh.face_normals()
mesh.face_colors()


# access vertex position, face index, normal, color, texcoord
vh0 = mesh.vertex_handle(0)
point = mesh.point(vh0)
eh0 = mesh.edge_handle(0)
heh = mesh.halfedge_handle(eh0, 0)
vh1 = mesh.from_vertex_handle(heh)
vh2 = mesh.to_vertex_handle(heh)
heh0 = mesh.prev_halfedge_handle(heh)
heh1 = mesh.next_halfedge_handle(heh)
heh0 = mesh.find_halfedge(vh1, vh2)
assert(heh0.is_valid())
assert(mesh.is_boundary(heh0))
mesh.set_color(vh1, [0., 0., 0., 1.])
mesh.set_texcoord2D(vh1, [0.5, 0.5])
mesh.set_normal(vh1, [0., 0., 0.])

mesh.update_normals()
mesh.update_face_normals()
mesh.update_vertex_normals()
mesh.update_halfedge_normals()
mesh.update_normal(vh0)

# seems unnecessary
mesh.has_vertex_normals()
# formats: mesh.<op>_<prop>()
# <op>: has / release / request
# <prop>:
#  vertex_normals, vertex_colors, vertex_texcoords<n>D (n = 1,2,3)
#  face_normals, face_colors, face_texture_index
#  edge_colors
#  halfedge_normals, halfedge_colors, halfedge_texcoords<n>D
#  <ele>_status, <ele>: vertex, face, halfedge, edge

# Iterators and Circulators
for vh1 in mesh.vertices():
    # iterate over the 1-ring of a vertex
    [vh.idx() for vh in mesh.vv(vh1)]
    # iterate over all incoming halfedges
    [heh.idx() for heh in mesh.vih(vh1)]
    # iterate over all outgoing halfedges
    [heh.idx() for heh in mesh.voh(vh1)]
    # iterate over all adjacent edges
    [eh.idx() for eh in mesh.ve(vh1)]
    # iterate over all adjacent faces
    [fh.idx() for fh in mesh.vf(vh1)]

for heh in mesh.halfedges():
    print(heh.idx())

for eh in mesh.edges():
    print(eh.idx())

for fh0 in mesh.faces():
    print(fh0.idx())
    # iterate over the face's vertices
    [vh.idx() for vh in mesh.fv(fh0)]
    # iterate over the face's halfedges
    [heh.idx() for heh in mesh.fh(fh0)]
    # iterate over the face's edges
    [eh.idx() for eh in mesh.fe(fh0)]
    # iterate over all edge-neighboring faces
    [fh.idx() for fh in mesh.ff(fh0)]


# indices
# vertex
indices = mesh.vv_indices()  # or mesh.vertex_vertex_indices()
indices = mesh.vf_indices()  # mesh.vertex_face_indices()
indices = mesh.ve_indices()  # mesh.vertex_edge_indices()
indices = mesh.voh_indices()  # mesh.vertex_outgoing_halfedge_indices()
indices = mesh.vih_indices()  # mesh.vertex_incoming_halfedge_indices()
# face
indices = mesh.fv_indices()  # mesh.face_vertex_indices()
indices = mesh.ff_indices()  # mesh.face_face_indices()
indices = mesh.fe_indices()  # mesh.face_edge_indices()
indices = mesh.fh_indices()  # mesh.face_halfedge_indices()
# edge
indices = mesh.ev_indices()  # mesh.edge_vertex_indices()
indices = mesh.ef_indices()  # mesh.edge_face_indices()
indices = mesh.eh_indices()  # mesh.edge_halfedge_indices()
# half edge
indices = mesh.hv_indices()  # mesh.halfedge_vertex_indices()
indices = mesh.htv_indices()  # mesh.halfedge_to_vertex_indices()
indices = mesh.hfv_indices()  # mesh.halfedge_from_vertex_indices()
indices = mesh.hf_indices()  # mesh.halfedge_face_indices()
indices = mesh.he_indices()  # mesh.halfedge_edge_indices()


# Mesh Manipulation
# add/delete geometry elements

# add vertices/faces
mesh = openmesh.TriMesh()
vh0 = mesh.add_vertex([0, 1, 0])
vh1 = mesh.add_vertex([1, 0, 0])
vh2 = mesh.add_vertex([2, 1, 0])
fh0 = mesh.add_face([vh0, vh1, vh2])  # or fh0 = mesh.add_face(vh0, vh1, vh2)

# init with arrays
points = mesh.points()
face_vertex_indices = mesh.face_vertex_indices()
mesh = openmesh.PolyMesh(points, face_vertex_indices)  # also openmesh.TriMesh

for vh in mesh.vertices():
    mesh.delete_vertex(vh)
mesh.delete_face(fh0, delete_isolated_vertices=True)
mesh.garbage_collection()

if mesh.is_collapse_ok(heh0):
    mesh.collapse(heh0)
if mesh.is_flip_ok(eh0):
    mesh.flip(eh0)
mesh.split(eh0, vh0)

# https://www.graphics.rwth-aachen.de:9000/OpenMesh/openmesh-python/tree/master/tests

Useful links:

• Homepage
• Python documentation
• Python official repository
• C++ documentation

Thanks a lot! This is much useful than the Python API's documentation.

Beware. Some of the functions do not work with the conda-forge version. It seems there are significant differences between the pip and conda versions

This is awesome thank you :)