why did the value of item2 change?

Question

Why did the value of item2 change after line 20? No where in the code have I redefined item2 so my expectation is it should not change. Is there any way to run the same code without changing the value of item2? Here is my code:

import  random   

def one(length):
    a = []
    for i in range(length):
        a.append(1)
    return(a)

def two(parent):
    b = parent
    if random.randint(0,10)<11:
        index = random.randint(0,6)
        b[index] = 6
    return b

item1 = one(6)
print(item1)
item2 = item1
print(item2)
item3 = two(item1)
print(item2)

And this is the result I'm getting:

[1,1,1,1,1,1]

[1,1,1,1,1,1]

[1,6,1,1,1,1]

This should help. https://stackoverflow.com/questions/4794244/how-can-i-create-a-copy-of-an-object-in-python — Rakesh, Jul 16 '18 at 12:33

score 0 · Accepted Answer · answered Jul 18 '18 at 11:09

0

change b = parent to b = parent[:] in line 10, answer provided by @rakesh

answered Jul 18 '18 at 11:09

gokul gupta

330
4
13

this worked perfectly, still dont understand why though (anyway it did the job) – gokul gupta Sep 04 '19 at 08:32

why did the value of item2 change?

1 Answers1