Help to find a command

[andre_fermart]

Thank you all for this valuable help!
I have learnt a lot and finally found the solution for my problem. Many others will come and let solve it one by one.

It worked for me as below.

tension = 0
count =0
while count<15:
    for link in chain:
        if tension > link[0] and len(link)==2:
            link.append(1)
            count =0
            
    tension += 1
    count +=1