Python的bug

Python太火了，不学点都感觉自己不是学计算机的，今天看了个不错的《简明python教程》，很不错。不过在学习过程中，居然发现了一个Python的bug，
#!/usr/bin/python
#coding=UTF-8
class Person:
'''Represents a person.'''
population = 0
def __init__(self, name):
'''Initializes the person's data.'''
self.name = name
print '(Initializing %s)' % self.name
Person.population += 1
def __del__(self):
'''I am dying'''
print '%s syas bye.' % self.name
Person.population -= 1
if Person.population == 0:
print 'I am the last one.'
else:
print 'There are still %d people left.' % \
Person.population
def sayHi(self):
'''Greeting by the person.
Really, that's all it does'''
print 'Hi, my name is %s.' % self.name
def howMany(self):
'''Prints the current population'''
if Person.population == 1:
print "I am the only person here"
else:
print 'We have %d persons here.' % Person.population
luolei = Person('luolei')
luolei.sayHi()
luolei.howMany()
xiaoming = Person('Xiao Ming')
xiaoming.sayHi()
xiaoming.howMany()
luolei.sayHi()
luolei.howMany() 
Person在对象析构之前先析构了，在对象析构的时候找不到类的说明了。
避免这个bug的办法是在luolei前面加上一个_，即变成_luolei则没有问题，因为python会先析构前面有下划线的变量，如此NB的Python居然有这么个明显的问题，困惑
Python的版本：Python 2.6.4