The ouput of one python challenge

Question

Though it looks like a very bad way to write the Python code, can anyone explain why the output is 122?
https://code.sololearn.com/c4IR36w7t3Od/?ref=app

Answer 1

n is a class variable. It is incremented each time a new object of this class is called and decremented when an object is deleted.

First, the a object is called, so n gets upped by 1 and is printed. Then, b is created, so n increases to 2 and is printed. Then, a is reinitialized - so it is deleted (n-=1) and re-created again (n+=1). So n stays at net 2 and is again printed.

Answer 2

@ Kuba Siekierzynski, thank you for your answer. If we change MyPc in the object definition into self, the output is different again. May I ask what is the difference?