python析构

__del__，析构函数不能手动调用，而是每个对象引用使用完之后系统自动回收垃圾，且按照字典顺序（A-Za-z）来回收。
class NewClass(object):
num_count = 0 # 所有的实例都共享此变量，即不单独为每个实例分配
def __init__(self,name):
self.name = name
NewClass.num_count += 1
def __del__(self):
NewClass.num_count -= 1
print ("Del",self.name)ewClass("Hello")
bb = aa
cc = aa
del bb,cc,aa
print ("Over")

__del__

Del Hello
Over

__del__

__del__

class NewClass(object):
num_count = 0 # 所有的实例都共享此变量，即不单独为每个实例分配
def __init__(self,name):
self.name = name
NewClass.num_count += 1
def __del__(self):
NewClass.num_count -= 1
print ("Del",self.name)
def test():
print ("aa")

aa = NewClass("Hello")
bb = aa
cc = aa
del bb,cc
print ("Over")

Over
Del Hello