line 1921 and 18 about callback?

Question

Error msg:

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Users\MISHIKA\AppData\Local\Programs\Python\Python310\lib\tkinter\__init__.py", line 1921, in __call__
    return self.func(*args)
  File "C:\Users\MISHIKA\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Python 3.10\tkinter\clsss46.py", line 18, in caltemp
    temp_f=temp1.get()
AttributeError: 'NoneType' object has no attribute 'get'

It's supposed to convert temperatures

full code:

from tkinter import *
from tkinter import messagebox
root=Tk()
root.title("Converter")
root.geometry("600x400")
def caltemp():
    var=StringVar()
    var.set("°C")
    temp1=Entry(root).grid(row=0, column=1)
    d1=OptionMenu(root, var, "°C", "°F").grid(row=0, column=2)
    lbl2=Label(root, text=" ").grid(row=0, column=3)
    if d1=="°C":
        temp_c=temp1.get()
        temp_f=(float(temp_c)*9/5)+32
        lbl2["text"]=f"{round(temp_f)}".grid(row=0, column=4)
        lbldeg=Label(root, text="°C").grid(row=0, column=5)
    else:
        temp_f=temp1.get()
        temp_c=(float(temp_f)-32)*5/9
        lbl2["text"]=f"{round(temp_c)}".grid(row=0, column=4)
        lbldeg=Label(root, text="°C").grid(row=0, column=5)
def temp():
    var=StringVar()
    var.set("°C")
    temp1=Entry(root).grid(row=0, column=1)
    d1=OptionMenu(root, var, "°C", "°F").grid(row=0, column=2)
    lblt=Label(root, text="≈")
    lbl2=Label(root, text=" ").grid(row=0, column=3)
    btntemp=Button(root, text="Calculate", command=caltemp).grid(row=1, column=3)
menu1=Menu(root)
menu1.add_command(label="Temperature", command=temp)
menu1.add_command(label="Length")
menu1.add_command(label="Currency")
root.config(menu=menu1)
root.mainloop()

score 0 · Answer 1 · answered Oct 28 '22 at 00:47

Take a look in my example.

import tkinter as tk
from tkinter import messagebox
from functools import partial

temp_Val = "Celsius"

def store_temp(set_temp):
    global temp_Val
    temp_Val = set_temp

def call_convert(rlabel1, inputn):
    temp = inputn.get()
    
    if temp_Val == 'Celsius':
        
        # Conversion of celsius temperature to fahrenheit
        f = float((float(temp) * 9 / 5) + 32)
        rlabel1.config(text ="%.1f Fahrenheit" % f)
        messagebox.showinfo("Temperature Converter",
                                    "Successfully converted to Fahrenheit ", )
        
    if temp_Val == 'Fahrenheit':
        
        # Conversion of fahrenheit temperature
        # to celsius
        c = float((float(temp) - 32) * 5 / 9)
        rlabel1.config(text ="%.1f Celsius" % c)
        messagebox.showinfo("Temperature Converter",
                                    "Successfully converted to Celsius ")
    return


root = tk.Tk()
root.geometry('300x150')
root.title('Temperature Converter')
root.grid_columnconfigure(1, weight = 1)
root.grid_rowconfigure(1, weight = 1)

inputNumber = tk.StringVar()
var = tk.StringVar()

input_label = tk.Label(root, text ="Enter temperature")
input_entry = tk.Entry(root, textvariable = inputNumber)
input_label.grid(row = 1)
input_entry.grid(row = 1, column = 1)
result_label = tk.Label(root)
result_label.grid(row = 3, columnspan = 4)

dropDownList = ["Celsius", "Fahrenheit"]
drop_down = tk.OptionMenu(root, var, *dropDownList,
                        command = store_temp)
var.set(dropDownList[0])
drop_down.grid(row = 1, column = 2)

call_convert = partial(call_convert, result_label,
                    inputNumber)
result_button = tk.Button(root, text ="Convert",
                        command = call_convert)
result_button.grid(row = 2, columnspan = 2)

root.mainloop()

line 1921 and 18 about callback?

1 Answers1