Is it possible to grab a label variable and put into list with tkinter

Question

I've created a temperature converter programme in which the calculated temperature from an entry widget gets displayed in a separate label, what I need to do is to grab that converted variable and put it into a list.

I think that making a connected entry widget to the label widget would work where they are connected so I could grab the variable using the .get method but that would look awfully messy. Is there any other way I could proceed with this?

This is my first post and I am a beginner in Python, very sorry if the code looks messy and if I included too much code.

data = []
tempVal = "Celcius"

def store_temp(sel_temp):
    global tempVal
    tempVal = sel_temp

class Calculator:
    def __init__(self, num_a, num_b):
        self.num_a= num_a
        self.num_b = num_b

def convert(self):
    if tempVal == 'Fahrenheit':
        return float((float(self.num_a) - 32)* 5 / 9)
    if tempVal == 'Celcius':
        return float((float(self.num_a) * 9/ 5) + 32)

def display_add(entry_numa,entry_numb,label_answer):
   #get the value from entry_numa
    num_a = entry_numa.get()
    num_b = entry_numb.get()

num_a = str(num_a)
num_b = str(num_b)
#create an object
global data
calc = Calculator(num_a,num_b)

label_answer['text'] = calc.convert()

data += [calc]

def calc_history():
global data 
#creat e another window
window_calc_list = Tk()
window_calc_list.geometry("400x200")

#create a listbox

listbox_calc_list = Listbox(window_calc_list, width= 300)
listbox_calc_list.pack()
listbox_calc_list.insert(END, "list of data")

for info in data:

   listbox_calc_list.insert(END, str(info.num_a) + " " + str(info.num_b) + " " )

window_calc_list.mainloop()

def main():
window = Tk()
window.geometry("500x150")

validate_letter = window.register(only_letters)
validate_nb = window.register(only_numbers_max_3)


label = Label(window, width = 30, background = 'lightblue', text='enter temperature, only numbers')
label.grid(row=0, column=0)

entry_numa = Entry(window, width = 30, validate="key", validatecommand=(validate_nb, '%d', '%P'))
entry_numa.grid(row = 0, column = 1)

#create another label and entry object for num_b

label_numb = Label(window, width = 30, background = 'lightblue', text='enter location, only letters')
label_numb.grid(row=1, column=0)

entry_numb = Entry(window, width = 30, validate="key", validatecommand=(validate_letter, '%d', '%S'))
entry_numb.grid(row = 1, column = 1)

#create another label to display answer
label_answer = Label(window, width = 30, background = 'lightyellow')
label_answer.grid(row = 2, column = 1)

entry_answer = Entry(window, width = 30)
entry_answer.grid(row = 2, column = 0)


button_add = Button(window, text = "ADD", command = lambda: display_add(entry_numa,entry_numb,label_answer))
button_add.grid(row=3, column = 0)


button_delete = Button(window, text = "DELETE", command = lambda: delete_data(data))
button_delete.grid(row=3, column = 2)

#create another button to display all previous calculations
button_display = Button(window,text = "calc_history", command = lambda: calc_history())
button_display.grid(row=3, column = 1)

var = StringVar()

dropDownList = ["Celcius", "Fahrenheit"]
dropdown = OptionMenu(window, var,dropDownList[0], *dropDownList, command=store_temp)
dropdown.grid(row=0, column=2)


window.mainloop()

Answer 1

A tk.Label displayed value can be accessed via the text property , labelwidgetname['text']. Depeneding on when and how you want the independent list of stored values to be updated there are a variety of options. The example shows one if the user is required to press a submission button. This could be adapted, for example,when the tempreture calculation is performed.

Of course it would be simpler to update the list of stored values directly at the point in the script where the calculated tempreture for the label text has been derived.

import tkinter as tk
stored_values = []

def add_labelvalue_tolist(temp):
    '''Store label value to list.'''
    stored_values.append(temp)
    print('contents of list', stored_values)

def add_entry_tolabel(event):
    display_label['text'] = user_entry.get()

ROOT = tk.Tk()

user_entry = tk.Entry()
user_entry.grid(column=0, row=0)
user_entry.bind('<KeyRelease>', add_entry_tolabel)
display_label = tk.Label()
display_label.grid(column=1, row=0)

# update list via button command linked to label text value
add_button = \
    tk.Button(text='add to list',
              command=lambda:add_labelvalue_tolist(display_label['text']))
add_button.grid(column=0, row=1)
ROOT.mainloop()

Answer 2

try making a function that is like this

def letterused():

    converter=(letter.get())# letter is a entry box at the bottom is the code

    converted.set(converter)

    for i in range(1):

        used_letters1.append(converter) #list

        letter = ttk.Entry(root, width = 20,textvariable = letter)
        letter.pack()