并行世界的线程

ERROR: duplicate key value violates unique constraint "table_pkey" DETAIL: Key (id)=(25) already exists.

这用方式比较方便：

$ ./manage.py sqlsequencereset app_name

基类和子类，如何在基类得到子类的类

class A(object):
   def __init__(self):
       print "A created"

   def a(self):
       print (self.__class__.__name__)
       print self.__class__.__bases__


class B(A):
   def __init__(self):
       pass
       # print super((B), self).__init__
       # print self.__class__.__name__
       # print super(B,self).__class__.__name__