Python3：語法無效

Question

我是一名Python初學者，並且一直在測試不同種類的示例代碼。當我開始使用Python3而不是2.7時;我遇到了一個語法錯誤，但我不明白如何解決這個錯誤。

File "app.py", line 101 
    except InvalidUserPass, e: 
         ^
SyntaxError: invalid syntax 

這裏是更多的代碼來給一些背景：

@app.route('/login/', methods=['GET', 'POST']) 
def login(): 
    error = None 
    if request.method == 'POST': 
     session['username'] = request.form['username'] 
     session['password'] = request.form['password'] 
     try: 
      # use reddit_api's login 
      r.login(user=session['username'], password=session['password']) 
     except InvalidUserPass, e: 
      error = 'Incorrect username or password. ' 
     if not error: 
      subreddits = r.user.get_my_reddits(limit=25) 
      my_reddits = [] 
      for i in range(25): 
       my_reddits.append(subreddits.next().display_name) 
      session['my_reddits'] = my_reddits 
      return redirect(url_for('index')) 
    return render_template('login.html', error=error) 

Answer 1

變化

except InvalidUserPass, e: 

到

except InvalidUserPass as e: 

更多信息，請參見this。

Answer 2

簡單except InvalidUserPass as e:。而對於上帝的份上，讓我們擺脫醜陋error件事：

@app.route('/login/', methods=['GET', 'POST']) 
def login(): 
    if request.method == 'POST': 
     session['username'] = request.form['username'] 
     session['password'] = request.form['password'] 

     try: 
      # use reddit_api's login 
      r.login(user=session['username'], password=session['password']) 
     except InvalidUserPass as e: 
      return render_template('login.html', 
            error='Incorrect username or password.') 

     subreddits = r.user.get_my_reddits(limit=25) 
     my_reddits = [] 
     for i in range(25): 
      my_reddits.append(subreddits.next().display_name) 
     session['my_reddits'] = my_reddits 
     return redirect(url_for('index')) 

    return render_template('login.html') 

Answer 3

在python3它是：

except InvalidUserPass as e: