How to prevent value change in python

Question

For example:

>>> state = (5,[1,2,3])
>>> current_state = state
>>> state[1].remove(3)
>>> state
(5, [1, 2])
>>> current_state
(5, [1, 2])

I changed the state but not current_state. How to keep the current_state value that equals (5,[1,2,3]) instead of removing 3 in python?

thanks!

Answer 1

One option would be to deepcopy state, so it and current_state refer to different objects:

>>> from copy import deepcopy
>>> state = (5,[1,2,3])
>>> current_state = deepcopy(state)
>>> state[1].remove(3)
>>> state
(5, [1, 2])
>>> current_state
(5, [1, 2, 3])