Python: random choice on matrix without selecting the number on the same line
<p>I have a problem because I would like realise a matrix by a random selection with replacement from the previous column without selecting the number that is on the same line as this element. </p>

<p>For example:</p>

<pre><code>#I create a matrix "pop" where there are numbers in the first and second column and where there are zeros on the other columns
tab = np.array([[3, 2, 1, 0, 4, 6], [9, 8, 7, 8, 2, 0]]) 
tab1=tab.transpose()
pop=np.zeros((6,8),int)
pop[:,0:2]=tab1

#I create a function "cuntage" which complete the matrix "pop" by a 
#random sampling with replacement  from the second previous column 
def countage (a):
    for i in range (0,6):
        pop[i,a]=np.random.choice(pop[:,(a-2)],1,replace=True)


# loope to complete the array "pop"
for r in range(2,8):
    countage(r)

pop
</code></pre>

<p>But the problem is that I would like select, by a random choice from second previous column, each element of the matrix but without selecting the number  that is on the same line as this element.</p>

<p>For example, in the matrix pop, the element pop[0,2] is select in pop[1:6,0].</p>

<p>Thanks for your responses!!</p>

<p>;-)</p>