immutable_and_mutable_variables.py

# -*- coding: utf-8 -*-
# Copyright (c) 2019, Silvio Peroni <essepuntato@gmail.com>
#
# Permission to use, copy, modify, and/or distribute this software for any purpose
# with or without fee is hereby granted, provided that the above copyright notice
# and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
# FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT,
# OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
# DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
# SOFTWARE.


# Immutable objects
my_num_1 = 41
my_num_2 = my_num_1
my_num_1 = my_num_1 + 1
print(my_num_1)  # 42
print(my_num_2)  # 41, since it is a copy of the original value

# Mutable objects
my_list_1 = list()
my_list_2 = my_list_1
my_list_1.append(1)
print(my_list_1)  # [1]
print(my_list_2)  # [1], since it points to the same list