Why is the output 1, 2, 2 and not 1, 2, 3?

Question

Why is the output 1, 2, 2 and not 1 2 3?

If I never delete any element the output is 1, 2, 2, now when I change in line 16 the variable a by c .. if I have a 1, 2, 3 output?

# https://code.sololearn.com/cmZL80XDJ5K3
1 class MyClass():
2 n = 5
3
4 def __init__(self):
5 MyClass.n += 1
6
7 def __del__(self):
8 MyClass.n -= 1
9
10 a = MyClass()
11 print (a.n)
12
13 b = MyClass()
14 print (b.n)
15
16 a = MyClass()
17 print (a.n)

Answer 1

The last assignment deletes 'a' variable (thus decreasing MyClass.n by one) and instantiates it again at the same time (thus increasing MyClass.n by one). So the balance is neutral :)