Create a copy of a list whose changes won't affect the initial list

Question

If I have a list like

a=[1,4,2]

and I create a new list in the following way

b=a

I found out that any modification to b would be applied to a as well:

b.sort()
print b
print a
b.pop(-1)
print b
print a

How can I create a copy of a list which I can modify at pleasure without affecting the original?

So, in my example, every time I print a I want to obtain the initial output [1,4,2], no matter what I do to b.

You need to use a deep copy operation. https://stackoverflow.com/questions/17873384/how-to-deep-copy-a-list — flyingmeatball, May 24 '19 at 17:01
If the values in your list are simple integers, you can create a copy with `b = a[:]` as @yatu commented. — John Gordon, May 24 '19 at 17:03

score 0 · Answer 1 · edited May 25 '19 at 02:05

0

use b =a.copy()

then use b.sort()

assert a==b

result False

edited May 25 '19 at 02:05

Eric Leschinski

answered May 24 '19 at 17:02

sahasrara62

1

@3sm1r it's working for you, that's matter. – sahasrara62 May 24 '19 at 20:02

1 Answers1