#	strings are immutable.
a = 'abcdefgh'
print(f"a: {a}")
print(f"a.upper(): {a.upper()}")
print(f"a: {a}")

#   As a comparison, lists are mutable
list_a = ['a', 'b', 'c']
list_b = list_a
list_c = list(list_a)
print(f"list_a: {list_a}")
print(f"list_b: {list_b}")
print(f"list_c: {list_c}")
print("result = list_a.append('d')")
result = list_a.append('d')
print(f"list_a: {list_a}")
print(f"list_b: {list_b}")
print(f"list_c: {list_c}")
print(f"result: {result}")