TypeError：“NoneType”对象在 Tkinter 中不可调用

Question

您好，我是 tkinter 新手，正在尝试一个简单的 Tkinter GUI，但出现错误：

TypeError: 'NoneType' 对象不可调用

这是我的代码：

from tkinter import *
from tkinter import filedialog
import pandas as pd
import pyodbc
from sqlalchemy import create_engine
import urllib

master = Tk()
master.title("Demo GUI")
master.geometry("900x400+150+150")
master.resizable(0,0)

def browse_file():
    global file_path
    global data_frame
    file_path = filedialog.askopenfilename(title = "Choose the file to upload")
    data_frame = pd.read_excel(file_path)

Label = Label(master,text="Choose the file to upload").grid(row=0)

Button = Button(master,text='Browse',command = browse_file).grid(row=0,column=1,pady=4)

Label_1 = Label(master,text="The file selected: "+file_path).grid(row=1,column=0)

master.mainloop()

我得到的错误是，

TypeError                                 Traceback (most recent call last)
<ipython-input-29-451372edd65a> in <module>
     25 Button = Button(master,text='Browse',command = browse_file).grid(row=0,column=1,pady=4)
     26 
---> 27 Label1 = Label(master,text="The file Choosen: "+file_path).grid(row=1,column=0)
     28 
     29 

TypeError: 'NoneType' object is not callable

Answer 1

'NoneType' 对象不可调用错误是由将对象放置在定义的位置引起的。 所以不是

Label_1 = Label(master,text="The file selected: "+file_path).grid(row=1,column=0)

试试：

Label(master,text="The file selected: "+file_path).grid(row=1,column=0)

或者

Label_1 = Label(master,text="The file selected: "+file_path)
Label_1.grid(row=1,column=0)

也不要使用 Button = Button(master... 而是给变量一个唯一的名称

Answer 2

您所做的错误是一个错字：通过写作：

Label = Label(master,text="Choose the file to upload").grid(row=0)

您将 grid 调用的结果分配给原始 tk.Label 类型 (Label)。网格回电是None

因此，当您尝试创建 Label1 时，您实际上是在调用 Label，现在是 None

只需将行替换为：

 l = Label(master,text="Choose the file to upload")
 l.grid(row=0)

或者干脆

Label(master,text="Choose the file to upload").grid(row=0)

Answer 3

这是答案：

from tkinter import *
from tkinter import filedialog
import tkinter as tk
import pandas as pd
import pyodbc
from sqlalchemy import create_engine
import urllib

master = Tk()
master.title("Demo GUI")
master.geometry("900x400+150+150")
master.resizable(0,0)

def browse_file():
    global file_path
    global data_frame
    file_path = filedialog.askopenfilename(title = "Choose the file to upload")
    data_frame = pd.read_excel(file_path)

Label = Label(master,text="Choose the file to upload").grid(row=0)

Button = Button(master,text='Browse',command = browse_file).grid(row=0,column=1,pady=4)

Label_1 = tk.Label(master,text="The file selected: "+file_path).grid(row=1,column=0)

master.mainloop()