Tkinter在搜索中沒有ascii錯誤

Question

我試圖在Tkinter中實現搜索。一切都運行完美而不list_box元素非ASCII字符（用於填充列表框列表變量然而，在搜索輸入非ASCII字符返回錯誤：

Exception in Tkinter callback 
Traceback (most recent call last): 
    File "/usr/lib/python2.7/lib-tk/Tkinter.py", line 1489, in __call__ 
    return self.func(*args) 
    File "ex2_af.py", line 20, in <lambda> 
    self.search_var.trace("w", lambda name, index, mode: self.update_list()) 
    File "ex2_af.py", line 41, in update_list 
    if search_term.lower() in item.lower(): 
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc5 in position 0: ordinal not in range(128) 

下面是代碼：

# -*- coding: utf-8 -*- 
from Tkinter import * 
# First create application class 
class Application(Frame): 
    def __init__(self, master=None): 
     Frame.__init__(self, master) 
     self.pack() 
     self.create_widgets() 
    # Create main GUI window 
    def create_widgets(self): 
     self.search_var = StringVar() 
     self.search_var.trace("w", lambda name, index, mode: self.update_list()) 
     self.entry = Entry(self, textvariable=self.search_var, width=13) 
     self.lbox = Listbox(self, width=45, height=15) 
     self.entry.grid(row=0, column=0, padx=10, pady=3) 
     self.lbox.grid(row=1, column=0, padx=10, pady=3) 
     # Function for updating the list/doing the search. 
     # It needs to be called here to populate the listbox. 
     self.update_list() 
    def update_list(self): 
     search_term = self.search_var.get() 
     # Last element, 'Čelo' represents non-ascii part. 
     # You may add any non-ascii to see what I'm talking about. 
     # How to access this element? 
     lbox_list = ['Adam', 'Lucy', 'Barry', 'Bob', 
     'James', 'Frank', 'Susan', 'Amanda', 'Christie', 'Čelo'] 
     self.lbox.delete(0, END) 
     for item in lbox_list: 
      if search_term.lower() in item.lower(): 
       self.lbox.insert(END, item) 
root = Tk() 
app = Application(master=root) 
app.mainloop() 

Answer 1

比較str和unicode（用戶輸入）（該lbox_list的項目）隱含嘗試使用默認編碼str對象轉換爲unicode（ASCII，除非另有配置）。

>>> u'Čelo' in 'Čelo' 
Traceback (most recent call last): 
    File "<stdin>", line 1, in <module> 
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc4 in position 0: ordinal not in range(128) 
>>> u'Čelo' in u'Čelo' 
True 

您可以通過避免這樣的隱式解碼通過定義列表作爲統一碼清單解決問題：

lbox_list = [               
    u'Adam', u'Lucy', u'Barry', u'Bob', 
    u'James', u'Frank', u'Susan', u'Amanda', u'Christie', 
    u'Čelo' 
]