[python2]local variable referenced before assignment问题

Question

class Test(obj):

def __init__(self):
    pass
    
def _is_flag(self):
    try:
        v_sql="""
        Select count(*)
          From tablename
        """
        push_ctrl_conn=oracle('ETL_TEST')
        self.reach_flag=push_ctrl_conn.runsql(v_sql,1)[0][0]
    except Exception,e:
        self._set_scan_state('22', str(e))
    finally:
        push_ctrl_conn.close()
        
def run(self):
    self._is_flag()

if name == '__main__':

test_case=Test()
test_case.run()

类似这种格式,然后就报了
UnboundLocalError: local variable 'push_ctrl_conn' referenced before assignment

Answer 1

try語法區塊不一定執行，即push_ctrl_conn不一定被賦值。很常見的錯誤，一般可以在try語法前先賦值。

像這種連線的需求，一般用上下文管理器功能，我猜oracle函式庫的實例也是支援的。