import time

# For small n, appending increases runtime every once a while
#n=10

# For large n, insertion takes much longer than appending
n=10000000

new_item = 5 # Some number

# Three lists [0,...,9]
mylist1 = range(n)
mylist2 = range(n)
mylist3 = range(n)


for i in range(50):
    # Replace value at index 3. List length stays the same.
    start1 = time.clock()
    mylist1[3]=new_item
    end1 = time.clock()

    # Append new value at end. List length increases.
    start2 = time.clock()
    mylist2.append(new_item)
    end2 =time.clock()

    # Insert new value at index 3. List length increases
    start3 = time.clock()
    mylist3.insert(3,new_item)
    end3 =time.clock()
    
    print i, "Replace: ", end1-start1,"\tAppend: ",end2-start2,
    print "\t Insert: ", end3-start3