import bpy

verts=[(0,0,0),(0,5,0),(5,5,0),(5,0,0),(0,0,5),(0,5,5),(5,5,5),(5,0,5)]
faces=[(0,1,2,3),(7,6,5,4),(0,4,5,1),(1,5,6,2),(2,6,7,3),(3,7,4,0)]

mymesh = bpy.data.meshes.new("Cube")
myobject = bpy.data.objects.new("Cube", mymesh)

myobject.location = bpy.context.scene.cursor.location 


bpy.context.collection.objects.link(myobject)


mymesh.from_pydata(verts,[],faces)
mymesh.update(calc_edges=True)