我找不出这个Tkinter错误

Question

我正在使用Python的Tkinter为我正在处理的项目创建一个GUI。

当我尝试虽然运行代码的一部分，我得到这个错误：

Traceback (most recent call last): 
    File "calculator.py", line 59, in <module> 
    app = Application() 
    File "calculator.py", line 28, in __init__ 
    self.create_widgets() 
    File "calculator.py", line 45, in create_widgets 
    self.special_chars.create_button(char, self.add_char_event(special_characters[char])) 
    File "calculator.py", line 20, in create_button 
    self.button_list += Button(self, text = txt, command = fcn) 
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ 
lib-tk/Tkinter.py", line 1206, in cget 
TypeError: cannot concatenate 'str' and 'int' objects 

的问题是，我无法找到文件的错误消息引用;我的python2.7/lib-tk文件夹只包含Tkinter的兼容版本（.pyo和.pyc）。

有没有办法找出发生了什么问题？

这里的calculator.py源

from Tkinter import * 
from exp import full_eval 
from maths import special_characters 

class special_char_frame(LabelFrame): 
    def __init__(self, master = None, text = 'Special Characters'): 
     LabelFrame.__init__(self, master) 
     self.grid() 
     self.button_list = [] 
    def create_button(self, txt, fcn): 
     self.button_list += Button(self, text = txt, command = fcn) 
     self.button_list[-1].grid(row = 0) 


class Application(Frame): 
    def __init__(self, master = None): 
     Frame.__init__(self, master) 
     self.grid() 
     self.create_widgets() 
    def create_widgets(self): 
     ## equation entry pane 
     self.text_entry = Entry(self, width = 100) 
     self.text_entry.grid(row = 0, column = 0) 
     self.text_entry.bind('<KeyPress-Return>', self.calculate) 
     ## result pane 
     self.result = StringVar() 
     self.result_label = Label(self, textvariable = self.result, wraplength = 815, justify = LEFT) 
     self.result_label.grid(row = 1, column = 0, columnspan = 2, sticky = W) 
     self.result.set('') 
     ## calculate button 
     self.calc_button = Button(self, text = 'Calculate', command = self.calculate) 
     self.calc_button.grid(row = 0, column = 1) 
     ## special character button pane 
     self.special_chars = special_char_frame(self) 
     for char in special_characters: 
      self.special_chars.create_button(char, self.add_char_event(special_characters[char])) 
     self.special_chars.grid(column = 0, columnspan = 2, row = 2) 
    def calculate(self, event = None): 
     try: 
      self.result.set(full_eval(self.text_entry.get())) 
     except Exception as error: 
      raise 
      #self.result.set(str(error)) 
     self.text_entry.select_range(0, END) 
    def add_char_event(self, char): 
     def add_char(self = self, event = None): 
      self.text_entry.insert(INSERT, char) 
     return add_char 

app = Application() 
app.master.title('Calculator') 
app.mainloop() 

full_eval是评估数学表达式的功能。

special_characters是一个字典，其中包含特殊字符及其解释。现在它只是special_characters = {'imaginary unit' : u'\u2148'}

Answer 1

好了，我该错过了第一次，但这个问题实际上是你正尝试将按钮添加到列表：

self.button_list += Button(self, text = txt, command = fcn) 

如果你简单地包裹在按钮托架，该错误消失（这是有道理的，因为你应该能够添加两个列表）：

self.button_list += [Button(self, text = txt, command = fcn)] 

---

ORIGINAL未遂

我的猜测：

special_characters是一本字典。它具有值为int s的键值映射。然后，当在self.text_entry.insert(INSERT, char)中使用时，text_entry试图向int中插入int并导致上述错误。简单的解决方案：在add_char中包装char与str。

def add_char_event(self, char): 
    def add_char(self = self, event = None): 
     self.text_entry.insert(INSERT, str(char)) 
    return add_char 

你的另一个选择是环绕special_characters查找STR：

for char in special_characters: 
     self.special_chars.create_button(char, 
      self.add_char_event(str(special_characters[char])))