How to randomly set elements in numpy array to 0

Question

First I create my array

myarray = np.random.random_integers(0,10, size=20)

Then, I want to set 20% of the elements in the array to 0 (or some o

Answer 1

If you want the 20% to be random:

random_list = []
array_len = len(myarray)

while len(random_list) < (array_len/5):
    random_int = math.randint(0,array_len)
    if random_int not in random_list:
        random_list.append(random_int)

for position in random_list:
    myarray[position] = 0

return myarray

This would ensure you definitely get 20% of the values, and RNG rolling the same number many times would not result in less than 20% of the values being 0.