I guess you are tryin to make a grid…
There’s a lot of silly things to start with.
The I gave up.
me=NMesh.GetRaw()
i=0 #you really don't need to initialise these
j=0
totalvert = 9
n = sqrt(totalvert) #this should really be cast to an integer here
for i in range(0, n, 1): # range(n) is sufficient
for j in range(0, n, 1): # range(n) is sufficient
v=NMesh.Vert(j, i, 0.0)
me.verts.append(v)
n0=int(n)
for i in range(0, n-1):
for j in range(0, n-1):
f=NMesh,Face()
f.v.append(me.vert[i*n0+j] # missing )
f.v.append(me.vert[i*n0+j+1] #and here
f.v.append(me.vert[(i+1)*n0+j+1] # and again
f.v.append(me.vert[(i+1)*no+j] # the var is called n0 not no
me.faces.append(f)
NMesh.PutRaw(me, "plane", 1)
Blender.Redraw()
BTW if you want to learn Python then buy a book.
O’Reilly has at least 2 excellent titles, you’ll save
yourself a lot of time and you’ll learn genuine
Python coding idioms.