generating randomitems from a list in python code example

Example: place a number randomly in a list python

offsetBiasSample = [randint(-10,10)/100 for i in range(10)]
offsetBias = choice(offsetBiasSample)
index_offsetBias = randint(0,len(oldBiases)-1)
oldBiases[index_offsetBias] = oldBiases[index_offsetBias] + offsetBias