Exception ignored in: <bound method Cursor.__del__ of <pypyodbc.Cursor object at 0x014621D0>>这是什么错误？

[omg21]

Exception ignored in: <bound method Cursor.__del__ of <pypyodbc.Cursor object at 0x014621D0>>
Traceback (most recent call last):
File "D:\Python34\lib\site-packages\pypyodbc-1.3.3-py3.4.egg\pypyodbc.py", line 2366, in __del__
File "D:\Python34\lib\site-packages\pypyodbc-1.3.3-py3.4.egg\pypyodbc.py", line 2348, in close
AttributeError: 'NoneType' object has no attribute 'SQLFreeStmt'
Exception ignored in: <bound method Connection.__del__ of <pypyodbc.Connection object at 0x00BB2B30>>
Traceback (most recent call last):
File "D:\Python34\lib\site-packages\pypyodbc-1.3.3-py3.4.egg\pypyodbc.py", line 2645, in __del__
File "D:\Python34\lib\site-packages\pypyodbc-1.3.3-py3.4.egg\pypyodbc.py", line 2658, in close
File "D:\Python34\lib\site-packages\pypyodbc-1.3.3-py3.4.egg\pypyodbc.py", line 2579, in rollback
TypeError: 'NoneType' object is not callable


我的环境是 XP ＋ Python34 ，之前一直都好好的，这几天总出这个错误，网上搜了半天也没找到解决方法。
这几天没有添加新的模块，这个错误也是时不时的出现，出现的比例大概占到五分之一吧，运行五次大概有一次出现这错误。

[omg21]

看了一下 pypy 的源代码，把错误行号标出来。

def __del__(self):
if not self.closed:
self.close() #2366 行


if self.connection.connected:
ret = ODBC_API.SQLFreeStmt(self.stmt_h, SQL_CLOSE) #2348 行
check_success(self, ret)


def __del__(self):
if self.connected:
self.close() #2645 行


if self.connected:
#if DEBUG:print 'disconnect'
if not self.autocommit:
self.rollback() #2658 行


def rollback(self):
if not self.connected:
raise ProgrammingError('HY000','Attempt to use a closed connection.') #2579 行
ret = SQLEndTran(SQL_HANDLE_DBC, self.dbc_h, SQL_ROLLBACK)
if ret != SQL_SUCCESS:
check_success(self, ret)

[omg21]

对了，前几天出了一个小插曲，我是用的 Sublime 编辑运行的，习惯同时打开好几个 py 文件，但是有一天突然出现一个现象，我在用 Ctrl+B 运行的时候，如果其他文件里有错误，会报错，导致没法运行，不过过了那阵子好像就没出过这个现象。