mylist = [64, 34, 25, 5, 22, 11, 90, 12]

​

n = len(mylist)

for i in range(n-1):

  min_index = i

  for j in range(i+1, n):

     if mylist[j] < mylist[min_index]:

       min_index = j

  min_value = mylist.pop(min_index)

  mylist.insert(i, min_value)

​

print(mylist)

​