[Numpy-discussion] Quikest way to create a diagonal matrix ?

[Pierre GM]

All,
What's the quickest way to create a diagonal matrix ? I already have the 
elements above the main diagonal. Of course, I could use loops:
>>>m=5
>>>z = numpy.arange(m*m).reshape(m,m)
>>>for k in range(m):
>>>    for j in range(k+1,m):
>>>        z[j,k] = z[k,j]
But I was looking for something more efficient.
Thanks a lot in advance !