[Python] Why constants in Python can be changed?

A constant is a variable whose value stays the same throughout the life of a program. Python doesn’t have built-in constant types, but Python programmers use all capital letters to indicate a variable should be treated as a constant and never be changed.

Here is an example:

num1 = 20
NUM = 40
print(NUM)

if num1 > 10:
NUM = NUM - 5
print(NUM)

Output:


40
35


I expected the constant NUM to not be changed, i.e. still be 40 and not 35, or get an error.

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