嘗試和除了返回錯誤，但是當沒有運行時，沒有發生錯誤？

Question

下面的代碼給我的問題：

def connect(self): 
    self.chatlog['state'] = NORMAL 
    self.chatlog.insert(END, ("===ATTEMPTING TO CONNECT TO SERVER\n")) 
    self.chatlog['state'] = DISABLED 
    self.chatlog.yview(END) 
    try: 
     s.connect((host,port)) 
     self.chatlog['state'] = NORMAL 
     self.chatlog.insert(END, ("===CONNECTED TO SERVER\n")) 
     self.chatlog['state'] = DISABLED 
     self.chatlog.yview(END) 
     self.conn=True 
     print("Connected") 

    except ConnectionRefusedError: 
     self.chatlog['state'] = NORMAL 
     self.chatlog.insert(END, ("===SERVER COULD NOT BE FOUND\n" + "===PLEASE MAKE SURE THE SERVER IS ON, AND YOU'RE CONNECTED TO THE NETWORK\n")) 
     self.chatlog['state'] = DISABLED 
     self.chatlog.yview(END) 
    else: 
     self.chatlog['state'] = NORMAL 
     self.chatlog.insert(END, ("===THERE'S AN ERROR WITH THE PROGRAM\n" + "===PLEASE TURN IT OFF AND ON AGAIN\n")) 
     self.chatlog['state'] = DISABLED 
     self.chatlog.yview(END) 

當我連接到服務器，它既連接（「試試看」的部分完成精細，打印語句時）但是「其他」部分也會發生。我似乎無法找到原因。有誰知道這是什麼原因？

編輯：我應該說，當我刪除「其他：」部分，它也可以很好地工作。

Answer 1

我猜你試圖捕捉所有的異常，但這不是正確的語法。

正確的方式做這將是：

try: 
    # do something dangerous 
except ConnectionRefusedError: 
    # handle known error 
except: 
    # handle unknown error 

else在這種情況下意味着，如果沒有發生錯誤的代碼會被執行。

Answer 2

一個try: except: else: finally:塊的else部分類似於else在if: else:，有效：

if someerror: 
    ... 
else: 
    ... 

的else塊運行時沒有錯誤被從try塊中引發。使用此塊允許您最小化try塊中的代碼;在你的情況下：

try: 
    s.connect((host,port))   
except ConnectionRefusedError: 
    self.chatlog['state'] = NORMAL 
    self.chatlog.insert(END, ("===SERVER COULD NOT BE FOUND\n" + "===PLEASE MAKE SURE THE SERVER IS ON, AND YOU'RE CONNECTED TO THE NETWORK\n")) 
    self.chatlog['state'] = DISABLED 
    self.chatlog.yview(END) 
else: 
    self.chatlog['state'] = NORMAL 
    self.chatlog.insert(END, ("===CONNECTED TO SERVER\n")) 
    self.chatlog['state'] = DISABLED 
    self.chatlog.yview(END) 
    self.conn=True 
    print("Connected")