[python2]local variable referenced before assignment問題

問題描述

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()

類似這種格式,然后就報了UnboundLocalError: local variable ’push_ctrl_conn’ referenced before assignment

問題解答

try語法塊不一定執行，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。

像這種連接的需求，一般用上下文管理器功能，我猜測oracle庫的實例也是支持的。