idempotent.py

#!/usr/bin/python3

def idempotent(other):
    myset={1,2,3}
    return myset.union(other)

def non_idempotent(other):
    mylist=[1,2,3]
    mylist.extend(other)
    return mylist

x=idempotent({100,200})
y=non_idempotent([100,200])

for i in range(1,5):
    print(str(i)+":    idempotent: "+str(x)+"     ||    non_idempotent: "+str(y))
    x=idempotent(x)
    y=non_idempotent(y)
    
    
    

# 1:    idempotent: {200, 1, 2, 3, 100}     ||    non_idempotent: [1, 2, 3, 100, 200]
# 2:    idempotent: {1, 2, 3, 100, 200}     ||    non_idempotent: [1, 2, 3, 1, 2, 3, 100, 200]
# 3:    idempotent: {1, 2, 3, 100, 200}     ||    non_idempotent: [1, 2, 3, 1, 2, 3, 1, 2, 3, 100, 200]
# 4:    idempotent: {1, 2, 3, 100, 200}     ||    non_idempotent: [1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3, 100, 200]