Simple program that demonstrates when writing to a class attribute in Python.

class_attr.py

# on line 11, we write to a CLASS attribute as opposed to an OBJECT attribute.

class Foo:
    x = 42

foo_1 = Foo()
foo_2 = Foo()

print(foo_1.a) # 42
foo_1.a = 99
print(foo_1.a) # 99
print(foo_2.a) # 42
Foo.a = 88 # changing the value of Foo's a
print(foo_1.a) # 99 (the value of foo_1's a)
print(foo_2.a) # 88 (the value of Foo's a)
del foo_1.a
print(foo_1.a) # 88